Science.gov

Sample records for effective query retrieval

  1. Retrieval with gene queries.

    PubMed

    Sehgal, Aditya K; Srinivasan, Padmini

    2006-04-21

    Accuracy of document retrieval from MEDLINE for gene queries is crucially important for many applications in bioinformatics. We explore five information retrieval-based methods to rank documents retrieved by PubMed gene queries for the human genome. The aim is to rank relevant documents higher in the retrieved list. We address the special challenges faced due to ambiguity in gene nomenclature: gene terms that refer to multiple genes, gene terms that are also English words, and gene terms that have other biological meanings. Our two baseline ranking strategies are quite similar in performance. Two of our three LocusLink-based strategies offer significant improvements. These methods work very well even when there is ambiguity in the gene terms. Our best ranking strategy offers significant improvements on three different kinds of ambiguities over our two baseline strategies (improvements range from 15.9% to 17.7% and 11.7% to 13.3% depending on the baseline). For most genes the best ranking query is one that is built from the LocusLink (now Entrez Gene) summary and product information along with the gene names and aliases. For others, the gene names and aliases suffice. We also present an approach that successfully predicts, for a given gene, which of these two ranking queries is more appropriate. We explore the effect of different post-retrieval strategies on the ranking of documents returned by PubMed for human gene queries. We have successfully applied some of these strategies to improve the ranking of relevant documents in the retrieved sets. This holds true even when various kinds of ambiguity are encountered. We feel that it would be very useful to apply strategies like ours on PubMed search results as these are not ordered by relevance in any way. This is especially so for queries that retrieve a large number of documents.

  2. Evaluating the Effectiveness of Information Retrieval Systems Using Simulated Queries.

    ERIC Educational Resources Information Center

    Gordon, Michael D.

    1990-01-01

    Describes a simulation method for estimating recall and fallout in a document retrieval system. Earlier research on simulating document retrieval systems is reviewed, examples are presented of the current method, a probabilistic justification of the method is given, theoretical concerns dealing with retrieval precision are discussed, and further…

  3. Effective Multi-Query Expansions: Collaborative Deep Networks for Robust Landmark Retrieval

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Lin, Xuemin; Wu, Lin; Zhang, Wenjie

    2017-03-01

    Given a query photo issued by a user (q-user), the landmark retrieval is to return a set of photos with their landmarks similar to those of the query, while the existing studies on the landmark retrieval focus on exploiting geometries of landmarks for similarity matches between candidate photos and a query photo. We observe that the same landmarks provided by different users over social media community may convey different geometry information depending on the viewpoints and/or angles, and may subsequently yield very different results. In fact, dealing with the landmarks with \\illshapes caused by the photography of q-users is often nontrivial and has seldom been studied. In this paper we propose a novel framework, namely multi-query expansions, to retrieve semantically robust landmarks by two steps. Firstly, we identify the top-$k$ photos regarding the latent topics of a query landmark to construct multi-query set so as to remedy its possible \\illshape. For this purpose, we significantly extend the techniques of Latent Dirichlet Allocation. Then, motivated by the typical \\emph{collaborative filtering} methods, we propose to learn a \\emph{collaborative} deep networks based semantically, nonlinear and high-level features over the latent factor for landmark photo as the training set, which is formed by matrix factorization over \\emph{collaborative} user-photo matrix regarding the multi-query set. The learned deep network is further applied to generate the features for all the other photos, meanwhile resulting into a compact multi-query set within such space. Extensive experiments are conducted on real-world social media data with both landmark photos together with their user information to show the superior performance over the existing methods.

  4. Effective Multi-Query Expansions: Collaborative Deep Networks for Robust Landmark Retrieval.

    PubMed

    Wang, Yang; Lin, Xuemin; Wu, Lin; Zhang, Wenjie

    2017-03-01

    Given a query photo issued by a user (q-user), the landmark retrieval is to return a set of photos with their landmarks similar to those of the query, while the existing studies on the landmark retrieval focus on exploiting geometries of landmarks for similarity matches between candidate photos and a query photo. We observe that the same landmarks provided by different users over social media community may convey different geometry information depending on the viewpoints and/or angles, and may, subsequently, yield very different results. In fact, dealing with the landmarks with low quality shapes caused by the photography of q-users is often nontrivial and has seldom been studied. In this paper, we propose a novel framework, namely, multi-query expansions, to retrieve semantically robust landmarks by two steps. First, we identify the top- k photos regarding the latent topics of a query landmark to construct multi-query set so as to remedy its possible low quality shape. For this purpose, we significantly extend the techniques of Latent Dirichlet Allocation. Then, motivated by the typical collaborative filtering methods, we propose to learn a collaborative deep networks-based semantically, nonlinear, and high-level features over the latent factor for landmark photo as the training set, which is formed by matrix factorization over collaborative user-photo matrix regarding the multi-query set. The learned deep network is further applied to generate the features for all the other photos, meanwhile resulting into a compact multi-query set within such space. Then, the final ranking scores are calculated over the high-level feature space between the multi-query set and all other photos, which are ranked to serve as the final ranking list of landmark retrieval. Extensive experiments are conducted on real-world social media data with both landmark photos together with their user information to show the superior performance over the existing methods, especially our recently

  5. Applying Query Structuring in Cross-language Retrieval.

    ERIC Educational Resources Information Center

    Pirkola, Ari; Puolamaki, Deniz; Jarvelin, Kalervo

    2003-01-01

    Explores ways to apply query structuring in cross-language information retrieval. Tested were: English queries translated into Finnish using an electronic dictionary, and run in a Finnish newspaper databases; effects of compound-based structuring using a proximity operator for translation equivalents of query language compound components; and a…

  6. Applying Query Structuring in Cross-language Retrieval.

    ERIC Educational Resources Information Center

    Pirkola, Ari; Puolamaki, Deniz; Jarvelin, Kalervo

    2003-01-01

    Explores ways to apply query structuring in cross-language information retrieval. Tested were: English queries translated into Finnish using an electronic dictionary, and run in a Finnish newspaper databases; effects of compound-based structuring using a proximity operator for translation equivalents of query language compound components; and a…

  7. Query-Time Optimization Techniques for Structured Queries in Information Retrieval

    ERIC Educational Resources Information Center

    Cartright, Marc-Allen

    2013-01-01

    The use of information retrieval (IR) systems is evolving towards larger, more complicated queries. Both the IR industrial and research communities have generated significant evidence indicating that in order to continue improving retrieval effectiveness, increases in retrieval model complexity may be unavoidable. From an operational perspective,…

  8. Query-Time Optimization Techniques for Structured Queries in Information Retrieval

    ERIC Educational Resources Information Center

    Cartright, Marc-Allen

    2013-01-01

    The use of information retrieval (IR) systems is evolving towards larger, more complicated queries. Both the IR industrial and research communities have generated significant evidence indicating that in order to continue improving retrieval effectiveness, increases in retrieval model complexity may be unavoidable. From an operational perspective,…

  9. A query theory account of the effect of memory retrieval on the sunk cost bias.

    PubMed

    Ting, Hsuchi; Wallsten, Thomas S

    2011-08-01

    The sunk cost bias occurs when individuals continue to invest in the same option when better alternatives are available. Many researchers believe that this bias is due to overemphasizing the past investment over the (missed) opportunities offered by alternatives. As an alternative or complement to this view, we show that memory retrieval and attention play important roles in the sunk cost bias. In two experiments, individuals generated more reasons for pursuing the invested option than for an alternative; they generated those reasons earlier in a sequence of reasons; and these effects increased as the individuals made progress toward attaining the reward yielded by the invested option. Associated with these effects, individuals perceived an increasingly wide gap in value between the invested and alternative options as they progressed toward the goal, thereby creating the sunk cost bias. Forcing individuals to reverse the order in which they generated reasons for the invested and alternative options reduced the bias. [corrected

  10. Information Retrieval Using UMLS-based Structured Queries

    PubMed Central

    Fagan, Lawrence M.; Berrios, Daniel C.; Chan, Albert; Cucina, Russell; Datta, Anupam; Shah, Maulik; Surendran, Sujith

    2001-01-01

    During the last three years, we have developed and described components of ELBook, a semantically based information-retrieval system [1-4]. Using these components, domain experts can specify a query model, indexers can use the query model to index documents, and end-users can search these documents for instances of indexed queries.

  11. Requirements for Query Evaluation in Weighted Information Retrieval.

    ERIC Educational Resources Information Center

    Bartschi, Martin

    1985-01-01

    Presents a general mathematical framework for information retrieval, in which query evaluation is seen as a mapping from the free term algebra built by query descriptors and weights to the semantic algebra of evaluation value. Competing mathematical models that try to describe how retrieval systems behave are reviewed. (Author/MBR)

  12. UWM-HBUT at TREC 2014 Microblog Track: Using Query Expansion (QE) and Event Identification Algorithm (EIA) to Improve Microblog Retrieval Effectiveness

    DTIC Science & Technology

    2014-11-01

    effectiveness. The ranking score of a retrieved tweet is adjusted by considering how close the tweet time stamp is to the event using Event Identification... stamp is to the event using Event Identification Algorithm (EIA). In addition, we also evaluate the Query Expansion (QE) approach using Google as an...an incremental clustering framework to detect new topics, employing a range of contents and temporal features to help in promptly detecting hot

  13. Applying Genetic Algorithms To Query Optimization in Document Retrieval.

    ERIC Educational Resources Information Center

    Horng, Jorng-Tzong; Yeh, Ching-Chang

    2000-01-01

    Proposes a novel approach to automatically retrieve keywords and then uses genetic algorithms to adapt the keyword weights. Discusses Chinese text retrieval, term frequency rating formulas, vector space models, bigrams, the PAT-tree structure for information retrieval, query vectors, and relevance feedback. (Author/LRW)

  14. Applying Genetic Algorithms To Query Optimization in Document Retrieval.

    ERIC Educational Resources Information Center

    Horng, Jorng-Tzong; Yeh, Ching-Chang

    2000-01-01

    Proposes a novel approach to automatically retrieve keywords and then uses genetic algorithms to adapt the keyword weights. Discusses Chinese text retrieval, term frequency rating formulas, vector space models, bigrams, the PAT-tree structure for information retrieval, query vectors, and relevance feedback. (Author/LRW)

  15. Boolean Queries and Term Dependencies in Probabilistic Retrieval Models.

    ERIC Educational Resources Information Center

    Croft, W. Bruce

    1986-01-01

    Proposes approach to integrating Boolean and statistical systems where Boolean queries are interpreted as a means of specifying term dependencies in relevant set of documents. Highlights include series of retrieval experiments designed to test retrieval strategy based on term dependence model and relation of results to other work. (18 references)…

  16. Effective retrieval in Hospital Information Systems: the use of context in answering queries to Patient Discharge Summaries.

    PubMed

    Nangle, B; Keane, M T

    1994-06-01

    The move towards the electronic storage of medical records in Hospital Information Systems (HISs) presents significant challenges for AI retrieval techniques. In this paper, we argue that adequate information retrieval in such systems will have to rely on the exploitation of the conceptual knowledge in those records rather than superficial string searches. However, this course of action is dependent on the developments of natural language processing techniques and on retrieval systems that can exploit semantic/conceptual knowledge. We present a retrieval system, which attempts to realise the second of these developments. This system, called CONIR [developed in the context of the European Community project MENELAS (AIM 2023)] operates in the domain of Patient Discharge Summaries on coronary illness. CONIR uses flexible retrieval techniques, that exploit conceptual context information, over a database of elaborated semantic records. In the course of the paper we outline the sorts of knowledge structures that are required to do this type of retrieval and indicate how they are constructed.

  17. Bat-Inspired Algorithm Based Query Expansion for Medical Web Information Retrieval.

    PubMed

    Khennak, Ilyes; Drias, Habiba

    2017-02-01

    With the increasing amount of medical data available on the Web, looking for health information has become one of the most widely searched topics on the Internet. Patients and people of several backgrounds are now using Web search engines to acquire medical information, including information about a specific disease, medical treatment or professional advice. Nonetheless, due to a lack of medical knowledge, many laypeople have difficulties in forming appropriate queries to articulate their inquiries, which deem their search queries to be imprecise due the use of unclear keywords. The use of these ambiguous and vague queries to describe the patients' needs has resulted in a failure of Web search engines to retrieve accurate and relevant information. One of the most natural and promising method to overcome this drawback is Query Expansion. In this paper, an original approach based on Bat Algorithm is proposed to improve the retrieval effectiveness of query expansion in medical field. In contrast to the existing literature, the proposed approach uses Bat Algorithm to find the best expanded query among a set of expanded query candidates, while maintaining low computational complexity. Moreover, this new approach allows the determination of the length of the expanded query empirically. Numerical results on MEDLINE, the on-line medical information database, show that the proposed approach is more effective and efficient compared to the baseline.

  18. Secure quantum private information retrieval using phase-encoded queries

    SciTech Connect

    Olejnik, Lukasz

    2011-08-15

    We propose a quantum solution to the classical private information retrieval (PIR) problem, which allows one to query a database in a private manner. The protocol offers privacy thresholds and allows the user to obtain information from a database in a way that offers the potential adversary, in this model the database owner, no possibility of deterministically establishing the query contents. This protocol may also be viewed as a solution to the symmetrically private information retrieval problem in that it can offer database security (inability for a querying user to steal its contents). Compared to classical solutions, the protocol offers substantial improvement in terms of communication complexity. In comparison with the recent quantum private queries [Phys. Rev. Lett. 100, 230502 (2008)] protocol, it is more efficient in terms of communication complexity and the number of rounds, while offering a clear privacy parameter. We discuss the security of the protocol and analyze its strengths and conclude that using this technique makes it challenging to obtain the unconditional (in the information-theoretic sense) privacy degree; nevertheless, in addition to being simple, the protocol still offers a privacy level. The oracle used in the protocol is inspired both by the classical computational PIR solutions as well as the Deutsch-Jozsa oracle.

  19. Secure quantum private information retrieval using phase-encoded queries

    NASA Astrophysics Data System (ADS)

    Olejnik, Lukasz

    2011-08-01

    We propose a quantum solution to the classical private information retrieval (PIR) problem, which allows one to query a database in a private manner. The protocol offers privacy thresholds and allows the user to obtain information from a database in a way that offers the potential adversary, in this model the database owner, no possibility of deterministically establishing the query contents. This protocol may also be viewed as a solution to the symmetrically private information retrieval problem in that it can offer database security (inability for a querying user to steal its contents). Compared to classical solutions, the protocol offers substantial improvement in terms of communication complexity. In comparison with the recent quantum private queries [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.100.230502 100, 230502 (2008)] protocol, it is more efficient in terms of communication complexity and the number of rounds, while offering a clear privacy parameter. We discuss the security of the protocol and analyze its strengths and conclude that using this technique makes it challenging to obtain the unconditional (in the information-theoretic sense) privacy degree; nevertheless, in addition to being simple, the protocol still offers a privacy level. The oracle used in the protocol is inspired both by the classical computational PIR solutions as well as the Deutsch-Jozsa oracle.

  20. Evaluating the Quality of Query Refinement Suggestions in Information Retrieval

    DTIC Science & Technology

    2006-01-01

    However, evaluating the effec- tiveness of these suggestions has remained quite subjective, with a vast majority of the past work relying on expensive...addressing the polysemy problem while QR suggestions can ef- fectively address both the problems. For example, query expansion may be able to retrieve...However, these evaluation measures can be quite expensive since it involves user interaction. Another work on evaluation that has similar objectives to the

  1. Knowledge Acquisition of Generic Queries for Information Retrieval

    PubMed Central

    Seol, Yoon-Ho; Johnson, Stephen B.; Cimino, James J.

    2002-01-01

    Several studies have identified clinical questions posed by health care professionals to understand the nature of information needs during clinical practice. To support access to digital information sources, it is necessary to integrate the information needs with a computer system. We have developed a conceptual guidance approach in information retrieval, based on a knowledge base that contains the patterns of information needs. The knowledge base uses a formal representation of clinical questions based on the UMLS knowledge sources, called the Generic Query model. To improve the coverage of the knowledge base, we investigated a method for extracting plausible clinical questions from the medical literature. This poster presents the Generic Query model, shows how it is used to represent the patterns of clinical questions, and describes the framework used to extract knowledge from the medical literature.

  2. Study of Query Expansion Techniques and Their Application in the Biomedical Information Retrieval

    PubMed Central

    Rivas, A. R.; Iglesias, E. L.; Borrajo, L.

    2014-01-01

    Information Retrieval focuses on finding documents whose content matches with a user query from a large document collection. As formulating well-designed queries is difficult for most users, it is necessary to use query expansion to retrieve relevant information. Query expansion techniques are widely applied for improving the efficiency of the textual information retrieval systems. These techniques help to overcome vocabulary mismatch issues by expanding the original query with additional relevant terms and reweighting the terms in the expanded query. In this paper, different text preprocessing and query expansion approaches are combined to improve the documents initially retrieved by a query in a scientific documental database. A corpus belonging to MEDLINE, called Cystic Fibrosis, is used as a knowledge source. Experimental results show that the proposed combinations of techniques greatly enhance the efficiency obtained by traditional queries. PMID:24723793

  3. Study of query expansion techniques and their application in the biomedical information retrieval.

    PubMed

    Rivas, A R; Iglesias, E L; Borrajo, L

    2014-01-01

    Information Retrieval focuses on finding documents whose content matches with a user query from a large document collection. As formulating well-designed queries is difficult for most users, it is necessary to use query expansion to retrieve relevant information. Query expansion techniques are widely applied for improving the efficiency of the textual information retrieval systems. These techniques help to overcome vocabulary mismatch issues by expanding the original query with additional relevant terms and reweighting the terms in the expanded query. In this paper, different text preprocessing and query expansion approaches are combined to improve the documents initially retrieved by a query in a scientific documental database. A corpus belonging to MEDLINE, called Cystic Fibrosis, is used as a knowledge source. Experimental results show that the proposed combinations of techniques greatly enhance the efficiency obtained by traditional queries.

  4. Query by Browsing: An Alternative Hypertext Information Retrieval Method

    PubMed Central

    Frisse, Mark E.; Cousins, Steve B.

    1989-01-01

    In this paper we discuss our efforts to develop programs which enhance the ability to navigate through large medical hypertext systems. Our approach organizes hypertext index terms into a belief network and uses reader feedback to update the degree of belief in the index terms' utility to a query. We begin by describing various possible configurations for indexes to hypertext. We then describe how belief network calculations can be applied to these indexes. After a brief discussion of early results using manuscripts from a medical handbook, we close with an analysis of our approach's applicability to a wider range of hypertext information retrieval problems.

  5. HDF5-FastQuery: An API for Simplifying Access to Data Storage,Retrieval, Indexing and Querying

    SciTech Connect

    Bethel, E. Wes; Gosink, Luke; Shalf, John; Stockinger, Kurt; Wu,Kesheng

    2006-06-15

    This work focuses on research and development activities that bridge a gap between fundamental data management technology index, query, storage and retrieval and use of such technology in computational and computer science algorithms and applications. The work has resulted in a streamlined applications programming interface (API) that simplifies data storage and retrieval using the HDF5 data I/O library, and eases use of the FastBit compressed bitmap indexing software for data indexing/querying. The API, which we call HDF5-FastQuery, will have broad applications in domain sciences as well as associated data analysis and visualization applications.

  6. EarthServer: Information Retrieval and Query Language

    NASA Astrophysics Data System (ADS)

    Perperis, Thanassis; Koltsida, Panagiota; Kakaletris, George

    2013-04-01

    Establishing open, unified, seamless, access and ad-hoc analytics on cross-disciplinary, multi-source, multi-dimensional, spatiotemporal Earth Science data of extreme-size and their supporting metadata are the main challenges of the EarthServer project (www.earthserver.eu), funded by the European Commission under its Seventh Framework Program. One of EarthServer's main objectives is to provide users with higher level coverage and metadata search, retrieval and processing capabilities to multi-disciplinary Earth Science data. Six Lighthouse Applications are being established, each one providing access to Cryospheric, Airborne, Atmospheric, Geology, Oceanography and Planetary science raster data repositories through strictly WCS 2.0 standard based service endpoints. EarthServers' information retrieval subsystem aims towards exploiting the WCS endpoints through a physically and logically distributed service oriented architecture, foreseeing the collaboration of several standard compliant services, capable of exploiting modern large grid and cloud infrastructures and of dynamically responding to availability and capabilities of underlying resources. Towards furthering technology for integrated, coherent service provision based on WCS and WCPS the concept of a query language (QL), unifying coverage and metadata processing and retrieval is introduced. EarthServer's information retrieval subsystem receives QL requests involving high volumes of all Earth Science data categories, executes them on the services that reside on the infrastructure and sends the results back to the requester through a high performance pipeline. In this contribution we briefly discuss EarthServer's service oriented coverage data and metadata search and retrieval architecture and further elaborate on the potentials of EarthServer's Query Language, called xWCPS (XQuery compliant WCPS). xWCPS aims towards merging the path that the two widely adopted standards (W3C XQuery, OGC WCPS) have paved, into a

  7. Framing memories: How the retrieval query format shapes the neural bases of remembering.

    PubMed

    Raposo, Ana; Frade, Sofia; Alves, Mara

    2016-08-01

    The way memory questions are framed influences the information that is searched, retrieved, and monitored during remembering. This fMRI study aimed at clarifying how the format of the retrieval query shapes the neural basis of source recollection. During encoding, participants made semantic (pleasantness) or perceptual (number of letters) judgments about words. Subsequently, in a source memory test, the retrieval query was manipulated such that for half of the items from each encoding task, the retrieval query emphasized the semantic source (i.e., semantic query format: "Is this word from the pleasantness task?"), whereas for the other half the retrieval query emphasized the alternate, perceptual source (i.e., perceptual query format: "Is this word from the letter task?"). The results showed that the semantic query format was associated with higher source recognition than the perceptual query format. This behavioral advantage was accompanied by increased activation in several regions associated to controlled semantic elaboration and monitoring of internally-generated features about the past event. In particular, for items semantically encoded, the semantic query, relative to the perceptual query, induced activation in medial prefrontal cortex (PFC), hippocampal, parahippocampal and middle temporal cortex. Conversely, for items perceptually encoded, the semantic query recruited the lateral PFC and occipital-fusiform areas. Interestingly, the semantic format also influenced the processing of new items, eliciting greater L lateral and medial PFC activation. In contrast, the perceptual query format (versus the semantic format) only prompted greater activation in R orbitofrontal cortex and the R inferior parietal lobe, for items encoded in a perceptual manner and for new items, respectively. The results highlight the role of the retrieval query format in source remembering, showing that the retrieval query that emphasizes the semantic source promotes the use of semantic

  8. Searching for Images: The Analysis of Users' Queries for Image Retrieval in American History.

    ERIC Educational Resources Information Center

    Choi, Youngok; Rasmussen, Edie M.

    2003-01-01

    Studied users' queries for visual information in American history to identify the image attributes important for retrieval and the characteristics of users' queries for digital images, based on queries from 38 faculty and graduate students. Results of pre- and post-test questionnaires and interviews suggest principle categories of search terms.…

  9. Searching for Images: The Analysis of Users' Queries for Image Retrieval in American History.

    ERIC Educational Resources Information Center

    Choi, Youngok; Rasmussen, Edie M.

    2003-01-01

    Studied users' queries for visual information in American history to identify the image attributes important for retrieval and the characteristics of users' queries for digital images, based on queries from 38 faculty and graduate students. Results of pre- and post-test questionnaires and interviews suggest principle categories of search terms.…

  10. Optimal query-based relevance feedback in medical image retrieval using score fusion-based classification.

    PubMed

    Behnam, Mohammad; Pourghassem, Hossein

    2015-04-01

    In this paper, a new content-based medical image retrieval (CBMIR) framework using an effective classification method and a novel relevance feedback (RF) approach are proposed. For a large-scale database with diverse collection of different modalities, query image classification is inevitable due to firstly, reducing the computational complexity and secondly, increasing influence of data fusion by removing unimportant data and focus on the more valuable information. Hence, we find probability distribution of classes in the database using Gaussian mixture model (GMM) for each feature descriptor and then using the fusion of obtained scores from the dependency probabilities, the most relevant clusters are identified for a given query. Afterwards, visual similarity of query image and images in relevant clusters are calculated. This method is performed separately on all feature descriptors, and then the results are fused together using feature similarity ranking level fusion algorithm. In the RF level, we propose a new approach to find the optimal queries based on relevant images. The main idea is based on density function estimation of positive images and strategy of moving toward the aggregation of estimated density function. The proposed framework has been evaluated on ImageCLEF 2005 database consisting of 10,000 medical X-ray images of 57 semantic classes. The experimental results show that compared with the existing CBMIR systems, our framework obtains the acceptable performance both in the image classification and in the image retrieval by RF.

  11. Medical case-based retrieval: integrating query MeSH terms for query-adaptive multi-modal fusion

    NASA Astrophysics Data System (ADS)

    Seco de Herrera, Alba G.; Foncubierta-Rodríguez, Antonio; Müller, Henning

    2015-03-01

    Advances in medical knowledge give clinicians more objective information for a diagnosis. Therefore, there is an increasing need for bibliographic search engines that can provide services helping to facilitate faster information search. The ImageCLEFmed benchmark proposes a medical case-based retrieval task. This task aims at retrieving articles from the biomedical literature that are relevant for differential diagnosis of query cases including a textual description and several images. In the context of this campaign many approaches have been investigated showing that the fusion of visual and text information can improve the precision of the retrieval. However, fusion does not always lead to better results. In this paper, a new query-adaptive fusion criterion to decide when to use multi-modal (text and visual) or only text approaches is presented. The proposed method integrates text information contained in MeSH (Medical Subject Headings) terms extracted and visual features of the images to find synonym relations between them. Given a text query, the query-adaptive fusion criterion decides when it is suitable to also use visual information for the retrieval. Results show that this approach can decide if a text or multi{modal approach should be used with 77.15% of accuracy.

  12. Improving biomedical information retrieval by linear combinations of different query expansion techniques.

    PubMed

    Abdulla, Ahmed AbdoAziz Ahmed; Lin, Hongfei; Xu, Bo; Banbhrani, Santosh Kumar

    2016-07-25

    Biomedical literature retrieval is becoming increasingly complex, and there is a fundamental need for advanced information retrieval systems. Information Retrieval (IR) programs scour unstructured materials such as text documents in large reserves of data that are usually stored on computers. IR is related to the representation, storage, and organization of information items, as well as to access. In IR one of the main problems is to determine which documents are relevant and which are not to the user's needs. Under the current regime, users cannot precisely construct queries in an accurate way to retrieve particular pieces of data from large reserves of data. Basic information retrieval systems are producing low-quality search results. In our proposed system for this paper we present a new technique to refine Information Retrieval searches to better represent the user's information need in order to enhance the performance of information retrieval by using different query expansion techniques and apply a linear combinations between them, where the combinations was linearly between two expansion results at one time. Query expansions expand the search query, for example, by finding synonyms and reweighting original terms. They provide significantly more focused, particularized search results than do basic search queries. The retrieval performance is measured by some variants of MAP (Mean Average Precision) and according to our experimental results, the combination of best results of query expansion is enhanced the retrieved documents and outperforms our baseline by 21.06 %, even it outperforms a previous study by 7.12 %. We propose several query expansion techniques and their combinations (linearly) to make user queries more cognizable to search engines and to produce higher-quality search results.

  13. The Limitations of Term Co-Occurrence Data for Query Expansion in Document Retrieval Systems.

    ERIC Educational Resources Information Center

    Peat, Helen J.; Willett, Peter

    1991-01-01

    Identifies limitations in the use of term co-occurrence data as a basis for automatic query expansion in natural language document retrieval systems. The use of similarity coefficients to calculate the degree of similarity between pairs of terms is explained, and frequency and discriminatory characteristics for nearest neighbors of query terms are…

  14. Natural Language Query System Design for Interactive Information Storage and Retrieval Systems. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Liu, I-Hsiung

    1985-01-01

    The currently developed multi-level language interfaces of information systems are generally designed for experienced users. These interfaces commonly ignore the nature and needs of the largest user group, i.e., casual users. This research identifies the importance of natural language query system research within information storage and retrieval system development; addresses the topics of developing such a query system; and finally, proposes a framework for the development of natural language query systems in order to facilitate the communication between casual users and information storage and retrieval systems.

  15. On-demand information retrieval in sensor networks with localised query and energy-balanced data collection.

    PubMed

    Teng, Rui; Zhang, Bing

    2011-01-01

    On-demand information retrieval enables users to query and collect up-to-date sensing information from sensor nodes. Since high energy efficiency is required in a sensor network, it is desirable to disseminate query messages with small traffic overhead and to collect sensing data with low energy consumption. However, on-demand query messages are generally forwarded to sensor nodes in network-wide broadcasts, which create large traffic overhead. In addition, since on-demand information retrieval may introduce intermittent and spatial data collections, the construction and maintenance of conventional aggregation structures such as clusters and chains will be at high cost. In this paper, we propose an on-demand information retrieval approach that exploits the name resolution of data queries according to the attribute and location of each sensor node. The proposed approach localises each query dissemination and enable localised data collection with maximised aggregation. To illustrate the effectiveness of the proposed approach, an analytical model that describes the criteria of sink proxy selection is provided. The evaluation results reveal that the proposed scheme significantly reduces energy consumption and improves the balance of energy consumption among sensor nodes by alleviating heavy traffic near the sink.

  16. Adaptation to Pronunciation Variations in Indonesian Spoken Query-Based Information Retrieval

    NASA Astrophysics Data System (ADS)

    Lestari, Dessi Puji; Furui, Sadaoki

    Recognition errors of proper nouns and foreign words significantly decrease the performance of ASR-based speech applications such as voice dialing systems, speech summarization, spoken document retrieval, and spoken query-based information retrieval (IR). The reason is that proper nouns and words that come from other languages are usually the most important key words. The loss of such words due to misrecognition in turn leads to a loss of significant information from the speech source. This paper focuses on how to improve the performance of Indonesian ASR by alleviating the problem of pronunciation variation of proper nouns and foreign words (English words in particular). To improve the proper noun recognition accuracy, proper-noun specific acoustic models are created by supervised adaptation using maximum likelihood linear regression (MLLR). To improve English word recognition, the pronunciation of English words contained in the lexicon is fixed by using rule-based English-to-Indonesian phoneme mapping. The effectiveness of the proposed method was confirmed through spoken query based Indonesian IR. We used Inference Network-based (IN-based) IR and compared its results with those of the classical Vector Space Model (VSM) IR, both using a tf-idf weighting schema. Experimental results show that IN-based IR outperforms VSM IR.

  17. Knowledge-Based Query Construction Using the CDSS Knowledge Base for Efficient Evidence Retrieval

    PubMed Central

    Afzal, Muhammad; Hussain, Maqbool; Ali, Taqdir; Hussain, Jamil; Khan, Wajahat Ali; Lee, Sungyoung; Kang, Byeong Ho

    2015-01-01

    Finding appropriate evidence to support clinical practices is always challenging, and the construction of a query to retrieve such evidence is a fundamental step. Typically, evidence is found using manual or semi-automatic methods, which are time-consuming and sometimes make it difficult to construct knowledge-based complex queries. To overcome the difficulty in constructing knowledge-based complex queries, we utilized the knowledge base (KB) of the clinical decision support system (CDSS), which has the potential to provide sufficient contextual information. To automatically construct knowledge-based complex queries, we designed methods to parse rule structure in KB of CDSS in order to determine an executable path and extract the terms by parsing the control structures and logic connectives used in the logic. The automatically constructed knowledge-based complex queries were executed on the PubMed search service to evaluate the results on the reduction of retrieved citations with high relevance. The average number of citations was reduced from 56,249 citations to 330 citations with the knowledge-based query construction approach, and relevance increased from 1 term to 6 terms on average. The ability to automatically retrieve relevant evidence maximizes efficiency for clinicians in terms of time, based on feedback collected from clinicians. This approach is generally useful in evidence-based medicine, especially in ambient assisted living environments where automation is highly important. PMID:26343669

  18. Query Enhancement with Topic Detection and Disambiguation for Robust Retrieval

    ERIC Educational Resources Information Center

    Zhang, Hui

    2013-01-01

    With the rapid increase in the amount of available information, people nowadays rely heavily on information retrieval (IR) systems such as web search engine to fulfill their information needs. However, due to the lack of domain knowledge and the limitation of natural language such as synonyms and polysemes, many system users cannot formulate their…

  19. Query Enhancement with Topic Detection and Disambiguation for Robust Retrieval

    ERIC Educational Resources Information Center

    Zhang, Hui

    2013-01-01

    With the rapid increase in the amount of available information, people nowadays rely heavily on information retrieval (IR) systems such as web search engine to fulfill their information needs. However, due to the lack of domain knowledge and the limitation of natural language such as synonyms and polysemes, many system users cannot formulate their…

  20. Improving Concept-Based Web Image Retrieval by Mixing Semantically Similar Greek Queries

    ERIC Educational Resources Information Center

    Lazarinis, Fotis

    2008-01-01

    Purpose: Image searching is a common activity for web users. Search engines offer image retrieval services based on textual queries. Previous studies have shown that web searching is more demanding when the search is not in English and does not use a Latin-based language. The aim of this paper is to explore the behaviour of the major search…

  1. Improving Concept-Based Web Image Retrieval by Mixing Semantically Similar Greek Queries

    ERIC Educational Resources Information Center

    Lazarinis, Fotis

    2008-01-01

    Purpose: Image searching is a common activity for web users. Search engines offer image retrieval services based on textual queries. Previous studies have shown that web searching is more demanding when the search is not in English and does not use a Latin-based language. The aim of this paper is to explore the behaviour of the major search…

  2. Integrating Boolean Queries in Conjunctive Normal Form with Probabilistic Retrieval Models.

    ERIC Educational Resources Information Center

    Losee, Robert M.; Bookstein, Abraham

    1988-01-01

    Presents a model that places Boolean database queries into conjunctive normal form, thereby allowing probabilistic ranking of documents and the incorporation of relevance feedback. Experimental results compare the performance of a sequential learning probabilistic retrieval model with the proposed integrated Boolean probabilistic model and a fuzzy…

  3. An Analysis of Ill-Formed Input in Natural Language Queries to Document Retrieval Systems.

    ERIC Educational Resources Information Center

    Young, Charlene W.; And Others

    1991-01-01

    Describes a study conducted at the University of South Carolina that examined the frequency of occurrence of several types of errors in a sample of natural language queries submitted by users requesting online searches in information retrieval systems. Implications for system design are suggested, including parsing systems. (28 references) (LRW)

  4. Clinical task-specific query expansion for the retrieval of scientifically rigorous research documents.

    PubMed

    Yoo, Sooyoung; Choi, Jinwook; Choi, Sungbin

    2010-01-01

    To support the practice of evidence-based medicine (EBM), clinically relevant and scientifically sound articles should be easily accessible. Due to the huge volume of medical literature and the low performance of present retrieval models, clinicians could only get relevant documents in the order of publication time. This study propose a new clinical task-specific retrieval technique that improves retrieval accuracy by exploiting clinical task-specific EBM terms to query expansion using co-occurrence analysis technique. The idea is aimed at selecting query expansion terms that are relevant to a specific clinical-task using task-specific EBM terms. Focusing on treatment and diagnosis tasks, the new method which was performed on the OHSUMED collection showed a further improved result than the existing method.

  5. Synonym, topic model and predicate-based query expansion for retrieving clinical documents.

    PubMed

    Zeng, Qing T; Redd, Doug; Rindflesch, Thomas; Nebeker, Jonathan

    2012-01-01

    We present a study that developed and tested three query expansion methods for the retrieval of clinical documents. Finding relevant documents in a large clinical data warehouse is a challenging task. To address this issue, first, we implemented a synonym expansion strategy that used a few selected vocabularies. Second, we trained a topic model on a large set of clinical documents, which was then used to identify related terms for query expansion. Third, we obtained related terms from a large predicate database derived from Medline abstracts for query expansion. The three expansion methods were tested on a set of clinical notes. All three methods successfully achieved higher average recalls and average F-measures when compared with the baseline method. The average precisions and precision at 10, however, decreased with all expansions. Amongst the three expansion methods, the topic model-based method performed the best in terms of recall and F-measure.

  6. A Query Analysis of Consumer Health Information Retrieval

    PubMed Central

    Hong, Yi; de la Cruz, Norberto; Barnas, Gary; Early, Eileen; Gillis, Rick

    2002-01-01

    The log files of MCW HealthLink web site were analyzed to study users' needs for consumer health information and get a better understanding of the health topics users are searching for, the paths users usually take to find consumer health information and the way to improve search effectiveness.

  7. Discovering biomedical semantic relations in PubMed queries for information retrieval and database curation.

    PubMed

    Huang, Chung-Chi; Lu, Zhiyong

    2016-01-01

    Identifying relevant papers from the literature is a common task in biocuration. Most current biomedical literature search systems primarily rely on matching user keywords. Semantic search, on the other hand, seeks to improve search accuracy by understanding the entities and contextual relations in user keywords. However, past research has mostly focused on semantically identifying biological entities (e.g. chemicals, diseases and genes) with little effort on discovering semantic relations. In this work, we aim to discover biomedical semantic relations in PubMed queries in an automated and unsupervised fashion. Specifically, we focus on extracting and understanding the contextual information (or context patterns) that is used by PubMed users to represent semantic relations between entities such as 'CHEMICAL-1 compared to CHEMICAL-2' With the advances in automatic named entity recognition, we first tag entities in PubMed queries and then use tagged entities as knowledge to recognize pattern semantics. More specifically, we transform PubMed queries into context patterns involving participating entities, which are subsequently projected to latent topics via latent semantic analysis (LSA) to avoid the data sparseness and specificity issues. Finally, we mine semantically similar contextual patterns or semantic relations based on LSA topic distributions. Our two separate evaluation experiments of chemical-chemical (CC) and chemical-disease (CD) relations show that the proposed approach significantly outperforms a baseline method, which simply measures pattern semantics by similarity in participating entities. The highest performance achieved by our approach is nearly 0.9 and 0.85 respectively for the CC and CD task when compared against the ground truth in terms of normalized discounted cumulative gain (nDCG), a standard measure of ranking quality. These results suggest that our approach can effectively identify and return related semantic patterns in a ranked order

  8. Discovering biomedical semantic relations in PubMed queries for information retrieval and database curation

    PubMed Central

    Huang, Chung-Chi; Lu, Zhiyong

    2016-01-01

    Identifying relevant papers from the literature is a common task in biocuration. Most current biomedical literature search systems primarily rely on matching user keywords. Semantic search, on the other hand, seeks to improve search accuracy by understanding the entities and contextual relations in user keywords. However, past research has mostly focused on semantically identifying biological entities (e.g. chemicals, diseases and genes) with little effort on discovering semantic relations. In this work, we aim to discover biomedical semantic relations in PubMed queries in an automated and unsupervised fashion. Specifically, we focus on extracting and understanding the contextual information (or context patterns) that is used by PubMed users to represent semantic relations between entities such as ‘CHEMICAL-1 compared to CHEMICAL-2.’ With the advances in automatic named entity recognition, we first tag entities in PubMed queries and then use tagged entities as knowledge to recognize pattern semantics. More specifically, we transform PubMed queries into context patterns involving participating entities, which are subsequently projected to latent topics via latent semantic analysis (LSA) to avoid the data sparseness and specificity issues. Finally, we mine semantically similar contextual patterns or semantic relations based on LSA topic distributions. Our two separate evaluation experiments of chemical-chemical (CC) and chemical–disease (CD) relations show that the proposed approach significantly outperforms a baseline method, which simply measures pattern semantics by similarity in participating entities. The highest performance achieved by our approach is nearly 0.9 and 0.85 respectively for the CC and CD task when compared against the ground truth in terms of normalized discounted cumulative gain (nDCG), a standard measure of ranking quality. These results suggest that our approach can effectively identify and return related semantic patterns in a ranked

  9. Visual graph query formulation and exploration: a new perspective on information retrieval at the edge

    NASA Astrophysics Data System (ADS)

    Kase, Sue E.; Vanni, Michelle; Knight, Joanne A.; Su, Yu; Yan, Xifeng

    2016-05-01

    Within operational environments decisions must be made quickly based on the information available. Identifying an appropriate knowledge base and accurately formulating a search query are critical tasks for decision-making effectiveness in dynamic situations. The spreading of graph data management tools to access large graph databases is a rapidly emerging research area of potential benefit to the intelligence community. A graph representation provides a natural way of modeling data in a wide variety of domains. Graph structures use nodes, edges, and properties to represent and store data. This research investigates the advantages of information search by graph query initiated by the analyst and interactively refined within the contextual dimensions of the answer space toward a solution. The paper introduces SLQ, a user-friendly graph querying system enabling the visual formulation of schemaless and structureless graph queries. SLQ is demonstrated with an intelligence analyst information search scenario focused on identifying individuals responsible for manufacturing a mosquito-hosted deadly virus. The scenario highlights the interactive construction of graph queries without prior training in complex query languages or graph databases, intuitive navigation through the problem space, and visualization of results in graphical format.

  10. Implementation of the common phrase index method on the phrase query for information retrieval

    NASA Astrophysics Data System (ADS)

    Fatmawati, Triyah; Zaman, Badrus; Werdiningsih, Indah

    2017-08-01

    As the development of technology, the process of finding information on the news text is easy, because the text of the news is not only distributed in print media, such as newspapers, but also in electronic media that can be accessed using the search engine. In the process of finding relevant documents on the search engine, a phrase often used as a query. The number of words that make up the phrase query and their position obviously affect the relevance of the document produced. As a result, the accuracy of the information obtained will be affected. Based on the outlined problem, the purpose of this research was to analyze the implementation of the common phrase index method on information retrieval. This research will be conducted in English news text and implemented on a prototype to determine the relevance level of the documents produced. The system is built with the stages of pre-processing, indexing, term weighting calculation, and cosine similarity calculation. Then the system will display the document search results in a sequence, based on the cosine similarity. Furthermore, system testing will be conducted using 100 documents and 20 queries. That result is then used for the evaluation stage. First, determine the relevant documents using kappa statistic calculation. Second, determine the system success rate using precision, recall, and F-measure calculation. In this research, the result of kappa statistic calculation was 0.71, so that the relevant documents are eligible for the system evaluation. Then the calculation of precision, recall, and F-measure produces precision of 0.37, recall of 0.50, and F-measure of 0.43. From this result can be said that the success rate of the system to produce relevant documents is low.

  11. Retrieval of diagnostic and treatment studies for clinical use through PubMed and PubMed's Clinical Queries filters

    PubMed Central

    Haynes, R Brian; Wilczynski, Nancy L; McKibbon, K Ann; Walter, Stephen D

    2011-01-01

    Objective Clinical Queries filters were developed to improve the retrieval of high-quality studies in searches on clinical matters. The study objective was to determine the yield of relevant citations and physician satisfaction while searching for diagnostic and treatment studies using the Clinical Queries page of PubMed compared with searching PubMed without these filters. Materials and methods Forty practicing physicians, presented with standardized treatment and diagnosis questions and one question of their choosing, entered search terms which were processed in a random, blinded fashion through PubMed alone and PubMed Clinical Queries. Participants rated search retrievals for applicability to the question at hand and satisfaction. Results For treatment, the primary outcome of retrieval of relevant articles was not significantly different between the groups, but a higher proportion of articles from the Clinical Queries searches met methodologic criteria (p=0.049), and more articles were published in core internal medicine journals (p=0.056). For diagnosis, the filtered results returned more relevant articles (p=0.031) and fewer irrelevant articles (overall retrieval less, p=0.023); participants needed to screen fewer articles before arriving at the first relevant citation (p<0.05). Relevance was also influenced by content terms used by participants in searching. Participants varied greatly in their search performance. Discussion Clinical Queries filtered searches returned more high-quality studies, though the retrieval of relevant articles was only statistically different between the groups for diagnosis questions. Conclusion Retrieving clinically important research studies from Medline is a challenging task for physicians. Methodological search filters can improve search retrieval. PMID:21680559

  12. Retrieval of diagnostic and treatment studies for clinical use through PubMed and PubMed's Clinical Queries filters.

    PubMed

    Lokker, Cynthia; Haynes, R Brian; Wilczynski, Nancy L; McKibbon, K Ann; Walter, Stephen D

    2011-01-01

    Clinical Queries filters were developed to improve the retrieval of high-quality studies in searches on clinical matters. The study objective was to determine the yield of relevant citations and physician satisfaction while searching for diagnostic and treatment studies using the Clinical Queries page of PubMed compared with searching PubMed without these filters. Forty practicing physicians, presented with standardized treatment and diagnosis questions and one question of their choosing, entered search terms which were processed in a random, blinded fashion through PubMed alone and PubMed Clinical Queries. Participants rated search retrievals for applicability to the question at hand and satisfaction. For treatment, the primary outcome of retrieval of relevant articles was not significantly different between the groups, but a higher proportion of articles from the Clinical Queries searches met methodologic criteria (p=0.049), and more articles were published in core internal medicine journals (p=0.056). For diagnosis, the filtered results returned more relevant articles (p=0.031) and fewer irrelevant articles (overall retrieval less, p=0.023); participants needed to screen fewer articles before arriving at the first relevant citation (p<0.05). Relevance was also influenced by content terms used by participants in searching. Participants varied greatly in their search performance. Clinical Queries filtered searches returned more high-quality studies, though the retrieval of relevant articles was only statistically different between the groups for diagnosis questions. Retrieving clinically important research studies from Medline is a challenging task for physicians. Methodological search filters can improve search retrieval.

  13. Automatic query generation using word embeddings for retrieving passages describing experimental methods

    PubMed Central

    Aydın, Ferhat; Hüsünbeyi, Zehra Melce; Özgür, Arzucan

    2017-01-01

    Information regarding the physical interactions among proteins is crucial, since protein–protein interactions (PPIs) are central for many biological processes. The experimental techniques used to verify PPIs are vital for characterizing and assessing the reliability of the identified PPIs. A lot of information about PPIs and the experimental methods are only available in the text of the scientific publications that report them. In this study, we approach the problem of identifying passages with experimental methods for physical interactions between proteins as an information retrieval search task. The baseline system is based on query matching, where the queries are generated by utilizing the names (including synonyms) of the experimental methods in the Proteomics Standard Initiative–Molecular Interactions (PSI-MI) ontology. We propose two methods, where the baseline queries are expanded by including additional relevant terms. The first method is a supervised approach, where the most salient terms for each experimental method are obtained by using the term frequency–relevance frequency (tf.rf) metric over 13 articles from our manually annotated data set of 30 full text articles, which is made publicly available. On the other hand, the second method is an unsupervised approach, where the queries for each experimental method are expanded by using the word embeddings of the names of the experimental methods in the PSI-MI ontology. The word embeddings are obtained by utilizing a large unlabeled full text corpus. The proposed methods are evaluated on the test set consisting of 17 articles. Both methods obtain higher recall scores compared with the baseline, with a loss in precision. Besides higher recall, the word embeddings based approach achieves higher F-measure than the baseline and the tf.rf based methods. We also show that incorporating gene name and interaction keyword identification leads to improved precision and F-measure scores for all three evaluated

  14. Automatic query generation using word embeddings for retrieving passages describing experimental methods.

    PubMed

    Aydın, Ferhat; Hüsünbeyi, Zehra Melce; Özgür, Arzucan

    2017-01-01

    Information regarding the physical interactions among proteins is crucial, since protein-protein interactions (PPIs) are central for many biological processes. The experimental techniques used to verify PPIs are vital for characterizing and assessing the reliability of the identified PPIs. A lot of information about PPIs and the experimental methods are only available in the text of the scientific publications that report them. In this study, we approach the problem of identifying passages with experimental methods for physical interactions between proteins as an information retrieval search task. The baseline system is based on query matching, where the queries are generated by utilizing the names (including synonyms) of the experimental methods in the Proteomics Standard Initiative-Molecular Interactions (PSI-MI) ontology. We propose two methods, where the baseline queries are expanded by including additional relevant terms. The first method is a supervised approach, where the most salient terms for each experimental method are obtained by using the term frequency-relevance frequency (tf.rf) metric over 13 articles from our manually annotated data set of 30 full text articles, which is made publicly available. On the other hand, the second method is an unsupervised approach, where the queries for each experimental method are expanded by using the word embeddings of the names of the experimental methods in the PSI-MI ontology. The word embeddings are obtained by utilizing a large unlabeled full text corpus. The proposed methods are evaluated on the test set consisting of 17 articles. Both methods obtain higher recall scores compared with the baseline, with a loss in precision. Besides higher recall, the word embeddings based approach achieves higher F-measure than the baseline and the tf.rf based methods. We also show that incorporating gene name and interaction keyword identification leads to improved precision and F-measure scores for all three evaluated methods

  15. Query-by-Sketch Image Retrieval Using Similarity in Stroke Order

    NASA Astrophysics Data System (ADS)

    Hisamori, Takashi; Arikawa, Toru; Ohashi, Gosuke

    In previous studies, the retrieval accuracy of large image databases has been improved as a result of reducing the semantic gap by combining the input sketch with relevance feedback. A further improvement of retrieval accuracy is expected by combining each stroke, and its order, of the input sketch with the relevance feedback. However, this leaves as a problem the fact that the effect of the relevance feedback substantially depends on the stroke order in the input sketch. Although it is theoretically possible to consider all the possible stroke orders, that would cause a realistic problem of creating an enormous amount of data. Consequently, the technique introduced in this paper intends to improve retrieval efficiency by effectively using the relevance feedback by means of conducting data mining of the sketch considering the similarity in the order of strokes. To ascertain the effectiveness of this technique, a retrieval experiment was conducted using 20, 000 images of a collection, the Corel Photo Gallery, and the experiment was able to confirm an improvement in the retrieval efficiency.

  16. LandEx - Fast, FOSS-Based Application for Query and Retrieval of Land Cover Patterns

    NASA Astrophysics Data System (ADS)

    Netzel, P.; Stepinski, T.

    2012-12-01

    The amount of satellite-based spatial data is continuously increasing making a development of efficient data search tools a priority. The bulk of existing research on searching satellite-gathered data concentrates on images and is based on the concept of Content-Based Image Retrieval (CBIR); however, available solutions are not efficient and robust enough to be put to use as deployable web-based search tools. Here we report on development of a practical, deployable tool that searches classified, rather than raw image. LandEx (Landscape Explorer) is a GeoWeb-based tool for Content-Based Pattern Retrieval (CBPR) contained within the National Land Cover Dataset 2006 (NLCD2006). The USGS-developed NLCD2006 is derived from Landsat multispectral images; it covers the entire conterminous U.S. with the resolution of 30 meters/pixel and it depicts 16 land cover classes. The size of NLCD2006 is about 10 Gpixels (161,000 x 100,000 pixels). LandEx is a multi-tier GeoWeb application based on Open Source Software. Main components are: GeoExt/OpenLayers (user interface), GeoServer (OGC WMS, WCS and WPS server), and GRASS (calculation engine). LandEx performs search using query-by-example approach: user selects a reference scene (exhibiting a chosen pattern of land cover classes) and the tool produces, in real time, a map indicating a degree of similarity between the reference pattern and all local patterns across the U.S. Scene pattern is encapsulated by a 2D histogram of classes and sizes of single-class clumps. Pattern similarity is based on the notion of mutual information. The resultant similarity map can be viewed and navigated in a web browser, or it can download as a GeoTiff file for more in-depth analysis. The LandEx is available at http://sil.uc.edu

  17. Cluster-Based Query Expansion Using Language Modeling for Biomedical Literature Retrieval

    ERIC Educational Resources Information Center

    Xu, Xuheng

    2011-01-01

    The tremendously huge volume of biomedical literature, scientists' specific information needs, long terms of multiples words, and fundamental problems of synonym and polysemy have been challenging issues facing the biomedical information retrieval community researchers. Search engines have significantly improved the efficiency and effectiveness of…

  18. Cluster-Based Query Expansion Using Language Modeling for Biomedical Literature Retrieval

    ERIC Educational Resources Information Center

    Xu, Xuheng

    2011-01-01

    The tremendously huge volume of biomedical literature, scientists' specific information needs, long terms of multiples words, and fundamental problems of synonym and polysemy have been challenging issues facing the biomedical information retrieval community researchers. Search engines have significantly improved the efficiency and effectiveness of…

  19. Cluster-based query expansion using external collections in medical information retrieval.

    PubMed

    Oh, Heung-Seon; Jung, Yuchul

    2015-12-01

    Utilizing external collections to improve retrieval performance is challenging research because various test collections are created for different purposes. Improving medical information retrieval has also gained much attention as various types of medical documents have become available to researchers ever since they started storing them in machine processable formats. In this paper, we propose an effective method of utilizing external collections based on the pseudo relevance feedback approach. Our method incorporates the structure of external collections in estimating individual components in the final feedback model. Extensive experiments on three medical collections (TREC CDS, CLEF eHealth, and OHSUMED) were performed, and the results were compared with a representative expansion approach utilizing the external collections to show the superiority of our method. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. GeoIRIS: Geospatial Information Retrieval and Indexing System—Content Mining, Semantics Modeling, and Complex Queries

    PubMed Central

    Shyu, Chi-Ren; Klaric, Matt; Scott, Grant J.; Barb, Adrian S.; Davis, Curt H.; Palaniappan, Kannappan

    2007-01-01

    Searching for relevant knowledge across heterogeneous geospatial databases requires an extensive knowledge of the semantic meaning of images, a keen eye for visual patterns, and efficient strategies for collecting and analyzing data with minimal human intervention. In this paper, we present our recently developed content-based multimodal Geospatial Information Retrieval and Indexing System (GeoIRIS) which includes automatic feature extraction, visual content mining from large-scale image databases, and high-dimensional database indexing for fast retrieval. Using these underpinnings, we have developed techniques for complex queries that merge information from heterogeneous geospatial databases, retrievals of objects based on shape and visual characteristics, analysis of multiobject relationships for the retrieval of objects in specific spatial configurations, and semantic models to link low-level image features with high-level visual descriptors. GeoIRIS brings this diverse set of technologies together into a coherent system with an aim of allowing image analysts to more rapidly identify relevant imagery. GeoIRIS is able to answer analysts’ questions in seconds, such as “given a query image, show me database satellite images that have similar objects and spatial relationship that are within a certain radius of a landmark.” PMID:18270555

  1. GeoIRIS: Geospatial Information Retrieval and Indexing System-Content Mining, Semantics Modeling, and Complex Queries.

    PubMed

    Shyu, Chi-Ren; Klaric, Matt; Scott, Grant J; Barb, Adrian S; Davis, Curt H; Palaniappan, Kannappan

    2007-04-01

    Searching for relevant knowledge across heterogeneous geospatial databases requires an extensive knowledge of the semantic meaning of images, a keen eye for visual patterns, and efficient strategies for collecting and analyzing data with minimal human intervention. In this paper, we present our recently developed content-based multimodal Geospatial Information Retrieval and Indexing System (GeoIRIS) which includes automatic feature extraction, visual content mining from large-scale image databases, and high-dimensional database indexing for fast retrieval. Using these underpinnings, we have developed techniques for complex queries that merge information from heterogeneous geospatial databases, retrievals of objects based on shape and visual characteristics, analysis of multiobject relationships for the retrieval of objects in specific spatial configurations, and semantic models to link low-level image features with high-level visual descriptors. GeoIRIS brings this diverse set of technologies together into a coherent system with an aim of allowing image analysts to more rapidly identify relevant imagery. GeoIRIS is able to answer analysts' questions in seconds, such as "given a query image, show me database satellite images that have similar objects and spatial relationship that are within a certain radius of a landmark."

  2. Retrieval Effectiveness by Semantic and Citation Searching.

    ERIC Educational Resources Information Center

    Pao, Miranda Lee; Worthen, Dennis B.

    1989-01-01

    Describes a pilot study in which a single database was constructed to provide access by both descriptors and cited references. For each query, two equivalent sets were retrieved and evaluated for relevance to the query. It is concluded that using both search methods can increase both recall and precision. (32 references) (CLB)

  3. IQARIS : a tool for the intelligent querying, analysis, and retrieval from information systems.

    SciTech Connect

    Hummel, J. R.; Silver, R. B.

    2002-04-26

    Information glut is one of the primary characteristics of the electronic age. Managing such large volumes of information (e.g., keeping track of the types, where they are, their relationships, who controls them, etc.) can be done efficiently with an intelligent, user-oriented information management system. The purpose of this paper is to describe a concept for managing information resources based on an intelligent information technology system developed by the Argonne National Laboratory for managing digital libraries. The Argonne system, Intelligent Query (IQ), enables users to query digital libraries and view the holdings that match the query from different perspectives.

  4. Content Based Retrieval Database Management System with Support for Similarity Searching and Query Refinement

    DTIC Science & Technology

    2002-01-01

    REFINEMENT BY MICHAEL ORTEGA–BINDERBERGER M.S., University of Illinois at Urbana Champaign, 1999 Ingeniero , Instituto Tecnológico Autónomo de...concept of query refinement. Instead of forcing users to manually modify the query, they can critique the results and and feed back this information to...capturing multimedia content using textual annotations, non-scalability of the approach to large data sets (due to the high degree of manual effort

  5. EFFECTIVENESS OF INFORMATION RETRIEVAL METHODS.

    ERIC Educational Resources Information Center

    SWETS, JOHN A.

    RESULTS OF FIFTY DIFFERENT RETRIEVAL METHODS AS APPLIED IN THREE EXPERIMENTAL RETRIEVAL SYSTEMS WERE SUBJECTED TO AN ANALYSIS SUGGESTED BY STATISTICAL DECISION THEORY. THE ANALYSIS USES A PREVIOUSLY-PROPOSED MEASURE OF EFFECTIVENESS AND DEMONSTRATES ITS SEVERAL PROPERTIES. SOME OF THESE PROPERTIES ARE--(1) IT ENABLES THE RETRIEVAL SYSTEM TO…

  6. Analysis of DNS cache effects on query distribution.

    PubMed

    Wang, Zheng

    2013-01-01

    This paper studies the DNS cache effects that occur on query distribution at the CN top-level domain (TLD) server. We first filter out the malformed DNS queries to purify the log data pollution according to six categories. A model for DNS resolution, more specifically DNS caching, is presented. We demonstrate the presence and magnitude of DNS cache effects and the cache sharing effects on the request distribution through analytic model and simulation. CN TLD log data results are provided and analyzed based on the cache model. The approximate TTL distribution for domain name is inferred quantificationally.

  7. Analysis of DNS Cache Effects on Query Distribution

    PubMed Central

    2013-01-01

    This paper studies the DNS cache effects that occur on query distribution at the CN top-level domain (TLD) server. We first filter out the malformed DNS queries to purify the log data pollution according to six categories. A model for DNS resolution, more specifically DNS caching, is presented. We demonstrate the presence and magnitude of DNS cache effects and the cache sharing effects on the request distribution through analytic model and simulation. CN TLD log data results are provided and analyzed based on the cache model. The approximate TTL distribution for domain name is inferred quantificationally. PMID:24396313

  8. Using Cause-Effect Relations in Text To Improve Information Retrieval Precision.

    ERIC Educational Resources Information Center

    Khoo, Christopher S. G.; Myaeng, Sung Hyon; Oddy, Robert N.

    2001-01-01

    This study used semantic relations expressed in text, particularly cause-effect relations, to improve information retrieval effectiveness. Investigated whether information obtained by matching cause-effect relations expressed in documents with the cause-effect relations expressed in users' queries can be used to improve retrieval results, in…

  9. Comment on "Secure quantum private information retrieval using phase-encoded queries"

    NASA Astrophysics Data System (ADS)

    Shi, Run-hua; Mu, Yi; Zhong, Hong; Zhang, Shun

    2016-12-01

    In this Comment, we reexamine the security of phase-encoded quantum private query (QPQ). We find that the current phase-encoded QPQ protocols, including their applications, are vulnerable to a probabilistic entangle-and-measure attack performed by the owner of the database. Furthermore, we discuss how to overcome this security loophole and present an improved cheat-sensitive QPQ protocol without losing the good features of the original protocol.

  10. Retrieval Effectiveness on the Web.

    ERIC Educational Resources Information Center

    Savoy, Jacques; Picard, Justin

    2001-01-01

    Discusses the role of search engines in Web usability and analyzes and evaluates the retrieval effectiveness of various indexing and searching strategies on a new Web text collection. Highlights include preprocessing techniques that might improve retrieval effectiveness; and hyperlinks as useful sources of evidence in improving retrieval…

  11. Indexing Depth and Retrieval Effectiveness

    ERIC Educational Resources Information Center

    Seely, Barbara J.

    1972-01-01

    There are six major studies of the effect of indexing depth on retrieval performance. They differ in purpose, methodology, measures, indexing language, field of study, and data base--nevertheless, all have found depth of indexing to have the same effect upon information retrieval. (13 references) (Author/NH)

  12. Analysis of Performance Variation Using Query Expansion.

    ERIC Educational Resources Information Center

    Alemayehu, Nega

    2003-01-01

    Discussion of information retrieval performance evaluation focuses on a case study using a statistical repeated measures analysis of variance for testing the significance of factors, such as retrieval method and topic in retrieval performance variation. Analyses of the effect of query expansion on document ranking confirm that expansion affects…

  13. Analysis of Performance Variation Using Query Expansion.

    ERIC Educational Resources Information Center

    Alemayehu, Nega

    2003-01-01

    Discussion of information retrieval performance evaluation focuses on a case study using a statistical repeated measures analysis of variance for testing the significance of factors, such as retrieval method and topic in retrieval performance variation. Analyses of the effect of query expansion on document ranking confirm that expansion affects…

  14. Natural language query system design for interactive information storage and retrieval systems. Presentation visuals. M.S. Thesis Final Report, 1 Jul. 1985 - 31 Dec. 1987

    NASA Technical Reports Server (NTRS)

    Dominick, Wayne D. (Editor); Liu, I-Hsiung

    1985-01-01

    This Working Paper Series entry represents a collection of presentation visuals associated with the companion report entitled Natural Language Query System Design for Interactive Information Storage and Retrieval Systems, USL/DBMS NASA/RECON Working Paper Series report number DBMS.NASA/RECON-17.

  15. Automatic Query Expansion via Lexical-Semantic Relationships.

    ERIC Educational Resources Information Center

    Greenberg, Jane

    2001-01-01

    Reports on an experiment that examined whether thesaurus terms, related to query in a specified semantic way (synonyms, narrower terms, related terms, or broader terms) could be identified as having a more positive impact on retrieval effectiveness when added to a query through automatic query expansion. (Contains 54 references.) (Author/LRW)

  16. Web image retrieval using an effective topic and content-based technique

    NASA Astrophysics Data System (ADS)

    Lee, Ching-Cheng; Prabhakara, Rashmi

    2005-03-01

    There has been an exponential growth in the amount of image data that is available on the World Wide Web since the early development of Internet. With such a large amount of information and image available and its usefulness, an effective image retrieval system is thus greatly needed. In this paper, we present an effective approach with both image matching and indexing techniques that improvise on existing integrated image retrieval methods. This technique follows a two-phase approach, integrating query by topic and query by example specification methods. In the first phase, The topic-based image retrieval is performed by using an improved text information retrieval (IR) technique that makes use of the structured format of HTML documents. This technique consists of a focused crawler that not only provides for the user to enter the keyword for the topic-based search but also, the scope in which the user wants to find the images. In the second phase, we use query by example specification to perform a low-level content-based image match in order to retrieve smaller and relatively closer results of the example image. From this, information related to the image feature is automatically extracted from the query image. The main objective of our approach is to develop a functional image search and indexing technique and to demonstrate that better retrieval results can be achieved.

  17. Effective Filtering of Query Results on Updated User Behavioral Profiles in Web Mining.

    PubMed

    Sadesh, S; Suganthe, R C

    2015-01-01

    Web with tremendous volume of information retrieves result for user related queries. With the rapid growth of web page recommendation, results retrieved based on data mining techniques did not offer higher performance filtering rate because relationships between user profile and queries were not analyzed in an extensive manner. At the same time, existing user profile based prediction in web data mining is not exhaustive in producing personalized result rate. To improve the query result rate on dynamics of user behavior over time, Hamilton Filtered Regime Switching User Query Probability (HFRS-UQP) framework is proposed. HFRS-UQP framework is split into two processes, where filtering and switching are carried out. The data mining based filtering in our research work uses the Hamilton Filtering framework to filter user result based on personalized information on automatic updated profiles through search engine. Maximized result is fetched, that is, filtered out with respect to user behavior profiles. The switching performs accurate filtering updated profiles using regime switching. The updating in profile change (i.e., switches) regime in HFRS-UQP framework identifies the second- and higher-order association of query result on the updated profiles. Experiment is conducted on factors such as personalized information search retrieval rate, filtering efficiency, and precision ratio.

  18. Query Expansion and Query Translation as Logical Inference.

    ERIC Educational Resources Information Center

    Nie, Jian-Yun

    2003-01-01

    Examines query expansion during query translation in cross language information retrieval and develops a general framework for inferential information retrieval in two particular contexts: using fuzzy logic and probability theory. Obtains evaluation formulas that are shown to strongly correspond to those used in other information retrieval models.…

  19. Query Expansion and Query Translation as Logical Inference.

    ERIC Educational Resources Information Center

    Nie, Jian-Yun

    2003-01-01

    Examines query expansion during query translation in cross language information retrieval and develops a general framework for inferential information retrieval in two particular contexts: using fuzzy logic and probability theory. Obtains evaluation formulas that are shown to strongly correspond to those used in other information retrieval models.…

  20. The Effects of Noisy Data on Text Retrieval.

    ERIC Educational Resources Information Center

    Taghva, Kazem; And Others

    1994-01-01

    Discusses the use of optical character recognition (OCR) for inputting documents in an information retrieval system and describes a study that used an OCR-generated database and its corresponding corrected version to examine query evaluation in the presence of noisy data. Scanning technology, recognition technology, and retrieval technology are…

  1. Effectively processing medical term queries on the UMLS Metathesaurus by layered dynamic programming

    PubMed Central

    2014-01-01

    Background Mapping medical terms to standardized UMLS concepts is a basic step for leveraging biomedical texts in data management and analysis. However, available methods and tools have major limitations in handling queries over the UMLS Metathesaurus that contain inaccurate query terms, which frequently appear in real world applications. Methods To provide a practical solution for this task, we propose a layered dynamic programming mapping (LDPMap) approach, which can efficiently handle these queries. LDPMap uses indexing and two layers of dynamic programming techniques to efficiently map a biomedical term to a UMLS concept. Results Our empirical study shows that LDPMap achieves much faster query speeds than LCS. In comparison to the UMLS Metathesaurus Browser and MetaMap, LDPMap is much more effective in querying the UMLS Metathesaurus for inaccurately spelled medical terms, long medical terms, and medical terms with special characters. Conclusions These results demonstrate that LDPMap is an efficient and effective method for mapping medical terms to the UMLS Metathesaurus. PMID:25079259

  2. Experiments in Multi-Lingual Information Retrieval.

    ERIC Educational Resources Information Center

    Salton, Gerard

    A comparison was made of the performance in an automatic information retrieval environment of user queries and document abstracts available in natural language form in both English and French. The results obtained indicate that the automatic indexing and retrieval techniques actually used appear equally effective in handling the query and document…

  3. A novel methodology for querying web images

    NASA Astrophysics Data System (ADS)

    Prabhakara, Rashmi; Lee, Ching Cheng

    2004-12-01

    Ever since the advent of Internet, there has been an immense growth in the amount of image data that is available on the World Wide Web. With such a magnitude of image availability, an efficient and effective image retrieval system is required to make use of this information. This research presents an effective image matching and indexing technique that improvises on existing integrated image retrieval methods. The proposed technique follows a two-phase approach, integrating query by topic and query by example specification methods. The first phase consists of topic-based image retrieval using an improved text information retrieval (IR) technique that makes use of the structured format of HTML documents. It consists of a focused crawler that not only provides for the user to enter the keyword for the topic-based search but also, the scope in which the user wants to find the images. The second phase uses the query by example specification to perform a low-level content-based image match for the retrieval of smaller and relatively closer results of the example image. Information related to the image feature is automatically extracted from the query image by the image processing system. A technique that is not computationally intensive based on color feature is used to perform content-based matching of images. The main goal is to develop a functional image search and indexing system and to demonstrate that better retrieval results can be achieved with this proposed hybrid search technique.

  4. A novel methodology for querying web images

    NASA Astrophysics Data System (ADS)

    Prabhakara, Rashmi; Lee, Ching Cheng

    2005-01-01

    Ever since the advent of Internet, there has been an immense growth in the amount of image data that is available on the World Wide Web. With such a magnitude of image availability, an efficient and effective image retrieval system is required to make use of this information. This research presents an effective image matching and indexing technique that improvises on existing integrated image retrieval methods. The proposed technique follows a two-phase approach, integrating query by topic and query by example specification methods. The first phase consists of topic-based image retrieval using an improved text information retrieval (IR) technique that makes use of the structured format of HTML documents. It consists of a focused crawler that not only provides for the user to enter the keyword for the topic-based search but also, the scope in which the user wants to find the images. The second phase uses the query by example specification to perform a low-level content-based image match for the retrieval of smaller and relatively closer results of the example image. Information related to the image feature is automatically extracted from the query image by the image processing system. A technique that is not computationally intensive based on color feature is used to perform content-based matching of images. The main goal is to develop a functional image search and indexing system and to demonstrate that better retrieval results can be achieved with this proposed hybrid search technique.

  5. Query Evaluation: Strategies and Optimizations.

    ERIC Educational Resources Information Center

    Turtle, Howard; Flood, James

    1995-01-01

    Discusses two query evaluation strategies used in large text retrieval systems: (1) term-at-a-time; and (2) document-at-a-time. Describes optimization techniques that can reduce query evaluation costs. Presents simulation results that compare the performance of these optimization techniques when applied to natural language query evaluation. (JMV)

  6. Object-based modeling, identification, and labeling of medical images for content-based retrieval by querying on intervals of attribute values

    NASA Astrophysics Data System (ADS)

    Thies, Christian; Ostwald, Tamara; Fischer, Benedikt; Lehmann, Thomas M.

    2005-04-01

    The classification and measuring of objects in medical images is important in radiological diagnostics and education, especially when using large databases as knowledge resources, for instance a picture archiving and communication system (PACS). The main challenge is the modeling of medical knowledge and the diagnostic context to label the sought objects. This task is referred to as closing the semantic gap between low-level pixel information and high level application knowledge. This work describes an approach which allows labeling of a-priori unknown objects in an intuitive way. Our approach consists of four main components. At first an image is completely decomposed into all visually relevant partitions on different scales. This provides a hierarchical organized set of regions. Afterwards, for each of the obtained regions a set of descriptive features is computed. In this data structure objects are represented by regions with characteristic attributes. The actual object identification is the formulation of a query. It consists of attributes on which intervals are defined describing those regions that correspond to the sought objects. Since the objects are a-priori unknown, they are described by a medical expert by means of an intuitive graphical user interface (GUI). This GUI is the fourth component. It enables complex object definitions by browsing the data structure and examinating the attributes to formulate the query. The query is executed and if the sought objects have not been identified its parameterization is refined. By using this heuristic approach, object models for hand radiographs have been developed to extract bones from a single hand in different anatomical contexts. This demonstrates the applicability of the labeling concept. By using a rule for metacarpal bones on a series of 105 images, this type of bone could be retrieved with a precision of 0.53 % and a recall of 0.6%.

  7. A Simple Blueprint for Automatic Boolean Query Processing.

    ERIC Educational Resources Information Center

    Salton, G.

    1988-01-01

    Describes a new Boolean retrieval environment in which an extended soft Boolean logic is used to automatically construct queries from original natural language formulations provided by users. Experimental results that compare the retrieval effectiveness of this method to conventional Boolean and vector processing are discussed. (27 references)…

  8. Producing approximate answers to database queries

    NASA Technical Reports Server (NTRS)

    Vrbsky, Susan V.; Liu, Jane W. S.

    1993-01-01

    We have designed and implemented a query processor, called APPROXIMATE, that makes approximate answers available if part of the database is unavailable or if there is not enough time to produce an exact answer. The accuracy of the approximate answers produced improves monotonically with the amount of data retrieved to produce the result. The exact answer is produced if all of the needed data are available and query processing is allowed to continue until completion. The monotone query processing algorithm of APPROXIMATE works within the standard relational algebra framework and can be implemented on a relational database system with little change to the relational architecture. We describe here the approximation semantics of APPROXIMATE that serves as the basis for meaningful approximations of both set-valued and single-valued queries. We show how APPROXIMATE is implemented to make effective use of semantic information, provided by an object-oriented view of the database, and describe the additional overhead required by APPROXIMATE.

  9. Web tools for effective retrieval, visualization, and evaluation of cardiology medical images and records

    NASA Astrophysics Data System (ADS)

    Masseroli, Marco; Pinciroli, Francesco

    2000-12-01

    To provide easy retrieval, integration and evaluation of multimodal cardiology images and data in a web browser environment, distributed application technologies and java programming were used to implement a client-server architecture based on software agents. The server side manages secure connections and queries to heterogeneous remote databases and file systems containing patient personal and clinical data. The client side is a Java applet running in a web browser and providing a friendly medical user interface to perform queries on patient and medical test dat and integrate and visualize properly the various query results. A set of tools based on Java Advanced Imaging API enables to process and analyze the retrieved cardiology images, and quantify their features in different regions of interest. The platform-independence Java technology makes the developed prototype easy to be managed in a centralized form and provided in each site where an intranet or internet connection can be located. Giving the healthcare providers effective tools for querying, visualizing and evaluating comprehensively cardiology medical images and records in all locations where they can need them- i.e. emergency, operating theaters, ward, or even outpatient clinics- the developed prototype represents an important aid in providing more efficient diagnoses and medical treatments.

  10. [Effective literature searching. Focusing the question and using PubMed queries].

    PubMed

    Kranke, P

    2004-03-01

    Apart from clinical and social expertise, the availability of contemporary knowledge is a key component in organisations within the health system that aim for excellence and competitiveness. Efficient literature searching is within this context a core business of evidence-based medicine. In addition to the need for valid data, the retrieval of information based on published literature has so far constituted a critical hurdle. Based on these requirements, two core issues for success with respect to literature searching are described: First, the generation of a structured question to form the basis of the most promising search terms. Second, a new feature of the web service of the national library of medicine, called "clinical queries", that allows the application of predefined filters to allocate clinically relevant data in terms of published clinical trials and systematic reviews.

  11. Interaction Information Retrieval.

    ERIC Educational Resources Information Center

    Dominich, Sandor

    1994-01-01

    Discussion of information retrieval focuses on an Interaction Information Retrieval model in which documents are interconnected; queries and documents are treated in the same way; and retrieval is the result of the interconnection between query and documents. A theoretical mathematical formulation of this type of retrieval is given. (Contains 31…

  12. Querying Proofs

    NASA Technical Reports Server (NTRS)

    Aspinall, David; Denney, Ewen; Lueth, Christoph

    2012-01-01

    We motivate and introduce a query language PrQL designed for inspecting machine representations of proofs. PrQL natively supports hiproofs which express proof structure using hierarchical nested labelled trees. The core language presented in this paper is locally structured (first-order), with queries built using recursion and patterns over proof structure and rule names. We define the syntax and semantics of locally structured queries, demonstrate their power, and sketch some implementation experiments.

  13. Relevant Term Suggestion in Interactive Web Search Based on Contextual Information in Query Session Logs.

    ERIC Educational Resources Information Center

    Huang, Chien-Kang; Chien, Lee-Feng; Oyang, Yen-Jen

    2003-01-01

    Proposes an effective term suggestion approach to interactive Web searches. Explains a log-based approach to relevant term extraction and term suggestion where relevant terms suggested for a user query are those that co-occur in similar query sessions from search engine logs rather than in the retrieved documents. (Author/LRW)

  14. Spatial Query for Planetary Data

    NASA Technical Reports Server (NTRS)

    Shams, Khawaja S.; Crockett, Thomas M.; Powell, Mark W.; Joswig, Joseph C.; Fox, Jason M.

    2011-01-01

    Science investigators need to quickly and effectively assess past observations of specific locations on a planetary surface. This innovation involves a location-based search technology that was adapted and applied to planetary science data to support a spatial query capability for mission operations software. High-performance location-based searching requires the use of spatial data structures for database organization. Spatial data structures are designed to organize datasets based on their coordinates in a way that is optimized for location-based retrieval. The particular spatial data structure that was adapted for planetary data search is the R+ tree.

  15. Retrieval-induced forgetting: dynamic effects between retrieval and restudy trials when practice is mixed.

    PubMed

    Dobler, Ina M; Bäuml, Karl-Heinz T

    2013-05-01

    Results from numerous previous studies suggest that when subjects study items from different categories and then repeatedly retrieve, or restudy, some of the items from some of the categories, repeated retrieval, but not repeated study, induces forgetting of related unpracticed items. We investigated in two experiments whether such effects of pure retrieval and pure study practice generalize to mixed practice-that is, when retrieval and restudy trials are randomly interleaved within a single experimental block. Experiment 1 employed cued recall; Experiment 2 employed item recognition testing. In both experiments, pure repeated retrieval, but not pure repeated study, caused forgetting of related unpracticed items, which is consistent with the prior work. In contrast, with mixed practice, both retrieval and restudy induced forgetting. Thus, whereas retrieval caused forgetting regardless of practice mode, restudy caused forgetting with mixed practice, but not with pure practice. The finding provides first evidence for dynamic effects between retrieval and restudy trials when practice is mixed. It is consistent with the view that, with mixed practice, subjects engage in more retrieval during restudy trials, so that restudy trials may trigger similar processes as retrieval trials and, thus, induce forgetting of related, not restudied, items.

  16. Retrieval-Based Learning: Positive Effects of Retrieval Practice in Elementary School Children.

    PubMed

    Karpicke, Jeffrey D; Blunt, Janell R; Smith, Megan A

    2016-01-01

    A wealth of research has demonstrated that practicing retrieval is a powerful way to enhance learning. However, nearly all prior research has examined retrieval practice with college students. Little is known about retrieval practice in children, and even less is known about possible individual differences in retrieval practice. In three experiments, 88 children (mean age 10 years) studied a list of words and either restudied the items or practiced retrieving them. They then took a final free recall test (Experiments 1 and 2) or recognition test (Experiment 3). In all experiments, children showed robust retrieval practice effects. Although a range of individual differences in reading comprehension and processing speed were observed among these children, the benefits of retrieval practice were independent of these factors. The results contribute to the growing body of research supporting the mnemonic benefits of retrieval practice and provide preliminary evidence that practicing retrieval may be an effective learning strategy for children with varying levels of reading comprehension and processing speed.

  17. Retrieval-Based Learning: Positive Effects of Retrieval Practice in Elementary School Children

    PubMed Central

    Karpicke, Jeffrey D.; Blunt, Janell R.; Smith, Megan A.

    2016-01-01

    A wealth of research has demonstrated that practicing retrieval is a powerful way to enhance learning. However, nearly all prior research has examined retrieval practice with college students. Little is known about retrieval practice in children, and even less is known about possible individual differences in retrieval practice. In three experiments, 88 children (mean age 10 years) studied a list of words and either restudied the items or practiced retrieving them. They then took a final free recall test (Experiments 1 and 2) or recognition test (Experiment 3). In all experiments, children showed robust retrieval practice effects. Although a range of individual differences in reading comprehension and processing speed were observed among these children, the benefits of retrieval practice were independent of these factors. The results contribute to the growing body of research supporting the mnemonic benefits of retrieval practice and provide preliminary evidence that practicing retrieval may be an effective learning strategy for children with varying levels of reading comprehension and processing speed. PMID:27014156

  18. Querying genomic databases

    SciTech Connect

    Baehr, A.; Hagstrom, R.; Joerg, D.; Overbeek, R.

    1991-09-01

    A natural-language interface has been developed that retrieves genomic information by using a simple subset of English. The interface spares the biologist from the task of learning database-specific query languages and computer programming. Currently, the interface deals with the E. coli genome. It can, however, be readily extended and shows promise as a means of easy access to other sequenced genomic databases as well.

  19. Variation in Relevance Judgments and the Measurement of Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Voorhees, Ellen M.

    2000-01-01

    Discusses the test collections developed in the TREC (Text REtrieval Conference) workshops for information retrieval research and describes a study by NIST (National Institute of Standards and Technology) that verified their reliability by investigating the effect changes in the relevance assessments have on the evaluation of retrieval results.…

  20. The Effect of Indexing Exhaustivity on Retrieval Performance.

    ERIC Educational Resources Information Center

    Burgin, Robert

    1991-01-01

    Describes results of a study that investigated the effect of variations in indexing exhaustivity on retrieval performance in a vector space retrieval system. The test collection of documents in the National Library of Medicine's Medline file indexed under cystic fibrosis is described, and use of the SMART information retrieval system is discussed.…

  1. The Effect of Indexing Exhaustivity on Retrieval Performance.

    ERIC Educational Resources Information Center

    Burgin, Robert

    1991-01-01

    Describes results of a study that investigated the effect of variations in indexing exhaustivity on retrieval performance in a vector space retrieval system. The test collection of documents in the National Library of Medicine's Medline file indexed under cystic fibrosis is described, and use of the SMART information retrieval system is discussed.…

  2. Variation in Relevance Judgments and the Measurement of Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Voorhees, Ellen M.

    2000-01-01

    Discusses the test collections developed in the TREC (Text REtrieval Conference) workshops for information retrieval research and describes a study by NIST (National Institute of Standards and Technology) that verified their reliability by investigating the effect changes in the relevance assessments have on the evaluation of retrieval results.…

  3. Analysis of queries sent to PubMed at the point of care: observation of search behaviour in a medical teaching hospital.

    PubMed

    Hoogendam, Arjen; Stalenhoef, Anton F H; Robbé, Pieter F de Vries; Overbeke, A John P M

    2008-09-24

    The use of PubMed to answer daily medical care questions is limited because it is challenging to retrieve a small set of relevant articles and time is restricted. Knowing what aspects of queries are likely to retrieve relevant articles can increase the effectiveness of PubMed searches. The objectives of our study were to identify queries that are likely to retrieve relevant articles by relating PubMed search techniques and tools to the number of articles retrieved and the selection of articles for further reading. This was a prospective observational study of queries regarding patient-related problems sent to PubMed by residents and internists in internal medicine working in an Academic Medical Centre. We analyzed queries, search results, query tools (Mesh, Limits, wildcards, operators), selection of abstract and full-text for further reading, using a portal that mimics PubMed. PubMed was used to solve 1121 patient-related problems, resulting in 3205 distinct queries. Abstracts were viewed in 999 (31%) of these queries, and in 126 (39%) of 321 queries using query tools. The average term count per query was 2.5. Abstracts were selected in more than 40% of queries using four or five terms, increasing to 63% if the use of four or five terms yielded 2-161 articles. Queries sent to PubMed by physicians at our hospital during daily medical care contain fewer than three terms. Queries using four to five terms, retrieving less than 161 article titles, are most likely to result in abstract viewing. PubMed search tools are used infrequently by our population and are less effective than the use of four or five terms. Methods to facilitate the formulation of precise queries, using more relevant terms, should be the focus of education and research.

  4. Analysis of queries sent to PubMed at the point of care: Observation of search behaviour in a medical teaching hospital

    PubMed Central

    Hoogendam, Arjen; Stalenhoef, Anton FH; Robbé, Pieter F de Vries; Overbeke, A John PM

    2008-01-01

    Background The use of PubMed to answer daily medical care questions is limited because it is challenging to retrieve a small set of relevant articles and time is restricted. Knowing what aspects of queries are likely to retrieve relevant articles can increase the effectiveness of PubMed searches. The objectives of our study were to identify queries that are likely to retrieve relevant articles by relating PubMed search techniques and tools to the number of articles retrieved and the selection of articles for further reading. Methods This was a prospective observational study of queries regarding patient-related problems sent to PubMed by residents and internists in internal medicine working in an Academic Medical Centre. We analyzed queries, search results, query tools (Mesh, Limits, wildcards, operators), selection of abstract and full-text for further reading, using a portal that mimics PubMed. Results PubMed was used to solve 1121 patient-related problems, resulting in 3205 distinct queries. Abstracts were viewed in 999 (31%) of these queries, and in 126 (39%) of 321 queries using query tools. The average term count per query was 2.5. Abstracts were selected in more than 40% of queries using four or five terms, increasing to 63% if the use of four or five terms yielded 2–161 articles. Conclusion Queries sent to PubMed by physicians at our hospital during daily medical care contain fewer than three terms. Queries using four to five terms, retrieving less than 161 article titles, are most likely to result in abstract viewing. PubMed search tools are used infrequently by our population and are less effective than the use of four or five terms. Methods to facilitate the formulation of precise queries, using more relevant terms, should be the focus of education and research. PMID:18816391

  5. Multiple Query Evaluation Based on an Enhanced Genetic Algorithm.

    ERIC Educational Resources Information Center

    Tamine, Lynda; Chrisment, Claude; Boughanem, Mohand

    2003-01-01

    Explains the use of genetic algorithms to combine results from multiple query evaluations to improve relevance in information retrieval. Discusses niching techniques, relevance feedback techniques, and evolution heuristics, and compares retrieval results obtained by both genetic multiple query evaluation and classical single query evaluation…

  6. Multiple Query Evaluation Based on an Enhanced Genetic Algorithm.

    ERIC Educational Resources Information Center

    Tamine, Lynda; Chrisment, Claude; Boughanem, Mohand

    2003-01-01

    Explains the use of genetic algorithms to combine results from multiple query evaluations to improve relevance in information retrieval. Discusses niching techniques, relevance feedback techniques, and evolution heuristics, and compares retrieval results obtained by both genetic multiple query evaluation and classical single query evaluation…

  7. Long-Term Health Effects of Neutering Dogs: Comparison of Labrador Retrievers with Golden Retrievers

    PubMed Central

    Hart, Benjamin L.; Hart, Lynette A.; Thigpen, Abigail P.; Willits, Neil H.

    2014-01-01

    Our recent study on the effects of neutering (including spaying) in Golden Retrievers in markedly increasing the incidence of two joint disorders and three cancers prompted this study and a comparison of Golden and Labrador Retrievers. Veterinary hospital records were examined over a 13-year period for the effects of neutering during specified age ranges: before 6 mo., and during 6–11 mo., year 1 or years 2 through 8. The joint disorders examined were hip dysplasia, cranial cruciate ligament tear and elbow dysplasia. The cancers examined were lymphosarcoma, hemangiosarcoma, mast cell tumor, and mammary cancer. The results for the Golden Retriever were similar to the previous study, but there were notable differences between breeds. In Labrador Retrievers, where about 5 percent of gonadally intact males and females had one or more joint disorders, neutering at <6 mo. doubled the incidence of one or more joint disorders in both sexes. In male and female Golden Retrievers, with the same 5 percent rate of joint disorders in intact dogs, neutering at <6 mo. increased the incidence of a joint disorder to 4–5 times that of intact dogs. The incidence of one or more cancers in female Labrador Retrievers increased slightly above the 3 percent level of intact females with neutering. In contrast, in female Golden Retrievers, with the same 3 percent rate of one or more cancers in intact females, neutering at all periods through 8 years of age increased the rate of at least one of the cancers by 3–4 times. In male Golden and Labrador Retrievers neutering had relatively minor effects in increasing the occurrence of cancers. Comparisons of cancers in the two breeds suggest that the occurrence of cancers in female Golden Retrievers is a reflection of particular vulnerability to gonadal hormone removal. PMID:25020045

  8. Searching Biases in Large Interactive Document Retrieval Systems.

    ERIC Educational Resources Information Center

    Journal of the American Society for Information Science, 1980

    1980-01-01

    Addresses the problem of systematic biases which affect the way that individuals construct and modify search queries on online retrieval systems, and suggests a searching algorithm that helps to avoid the effect of those biases. (FM)

  9. Retrieval procedure of effective conductivity for plasmonic resonant anisotropic metasurface

    NASA Astrophysics Data System (ADS)

    Yermakov, O. Y.; Porubaev, F.; Bogdanov, A. A.; Samusev, A. K.; Iorsh, I. V.

    2017-09-01

    In this work we introduce the effective surface conductivity retrieval procedure in order to describe the properties of plasmonic resonant anisotropic metasurface consisting of plasmonic elliptical nanodisks.

  10. Surface Emissivity Effects on Thermodynamic Retrieval of IR Spectral Radiance

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Larar, Allen M.; Smith, William L.; Liu, Xu

    2006-01-01

    The surface emissivity effect on the thermodynamic parameters (e.g., the surface skin temperature, atmospheric temperature, and moisture) retrieved from satellite infrared (IR) spectral radiance is studied. Simulation analysis demonstrates that surface emissivity plays an important role in retrieval of surface skin temperature and terrestrial boundary layer (TBL) moisture. NAST-I ultraspectral data collected during the CLAMS field campaign are used to retrieve thermodynamic properties of the atmosphere and surface. The retrievals are then validated by coincident in-situ measurements, such as sea surface temperature, radiosonde temperature and moisture profiles. Retrieved surface emissivity is also validated by that computed from the observed radiance and calculated emissions based on the retrievals of surface temperature and atmospheric profiles. In addition, retrieved surface skin temperature and emissivity are validated together by radiance comparison between the observation and retrieval-based calculation in the window region where atmospheric contribution is minimized. Both simulation and validation results have lead to the conclusion that variable surface emissivity in the inversion process is needed to obtain accurate retrievals from satellite IR spectral radiance measurements. Retrieval examples are presented to reveal that surface emissivity plays a significant role in retrieving accurate surface skin temperature and TBL thermodynamic parameters.

  11. Manchester visual query language

    NASA Astrophysics Data System (ADS)

    Oakley, John P.; Davis, Darryl N.; Shann, Richard T.

    1993-04-01

    We report a database language for visual retrieval which allows queries on image feature information which has been computed and stored along with images. The language is novel in that it provides facilities for dealing with feature data which has actually been obtained from image analysis. Each line in the Manchester Visual Query Language (MVQL) takes a set of objects as input and produces another, usually smaller, set as output. The MVQL constructs are mainly based on proven operators from the field of digital image analysis. An example is the Hough-group operator which takes as input a specification for the objects to be grouped, a specification for the relevant Hough space, and a definition of the voting rule. The output is a ranked list of high scoring bins. The query could be directed towards one particular image or an entire image database, in the latter case the bins in the output list would in general be associated with different images. We have implemented MVQL in two layers. The command interpreter is a Lisp program which maps each MVQL line to a sequence of commands which are used to control a specialized database engine. The latter is a hybrid graph/relational system which provides low-level support for inheritance and schema evolution. In the paper we outline the language and provide examples of useful queries. We also describe our solution to the engineering problems associated with the implementation of MVQL.

  12. The Effect of Episodic Retrieval on Inhibition in Task Switching.

    PubMed

    Grange, James A; Kowalczyk, Agnieszka W; O'Loughlin, Rory

    2017-04-06

    Inhibition in task switching is inferred from n-2 repetition costs: the observation that ABA task switching sequences are responded to slower than CBA sequences. This is thought to reflect the persisting inhibition of Task A, which slows reactivation attempts. Mayr (2002) reported an experiment testing a critical noninhibitory account of this effect, namely episodic retrieval: If the trial parameters for Task A match across an ABA sequence, responses should be facilitated because of priming from episodic retrieval; a cost would occur if trial parameters mismatch. In a rule-switching paradigm, Mayr reported no significant difference in n-2 repetition cost when the trial parameters repeated or switched across an ABA sequence, in clear contrast to the episodic retrieval account. What remains unclear is whether successful episodic retrieval modulates the n-2 repetition cost. Across 3 experiments-including a close replication of Mayr-we find clear evidence of reduced n-2 task repetition costs when episodic retrieval is controlled. We find that the effect of episodic retrieval on the n-2 task repetition cost is increased when the cue-task relationship is made more abstract, suggesting the effect is because of interference in establishing the relevant attentional set. We also demonstrate that the episodic retrieval effect is not influenced by retrieval of low-level, perceptual, elements. Together, the data suggest the n-2 task repetition cost-typically attributable to an inhibitory mechanism-also reflects episodic retrieval effects. (PsycINFO Database Record

  13. Boolean versus ranked querying for biomedical systematic reviews

    PubMed Central

    2010-01-01

    Background The process of constructing a systematic review, a document that compiles the published evidence pertaining to a specified medical topic, is intensely time-consuming, often taking a team of researchers over a year, with the identification of relevant published research comprising a substantial portion of the effort. The standard paradigm for this information-seeking task is to use Boolean search; however, this leaves the user(s) the requirement of examining every returned result. Further, our experience is that effective Boolean queries for this specific task are extremely difficult to formulate and typically require multiple iterations of refinement before being finalized. Methods We explore the effectiveness of using ranked retrieval as compared to Boolean querying for the purpose of constructing a systematic review. We conduct a series of experiments involving ranked retrieval, using queries defined methodologically, in an effort to understand the practicalities of incorporating ranked retrieval into the systematic search task. Results Our results show that ranked retrieval by itself is not viable for this search task requiring high recall. However, we describe a refinement of the standard Boolean search process and show that ranking within a Boolean result set can improve the overall search performance by providing early indication of the quality of the results, thereby speeding up the iterative query-refinement process. Conclusions Outcomes of experiments suggest that an interactive query-development process using a hybrid ranked and Boolean retrieval system has the potential for significant time-savings over the current search process in the systematic reviewing. PMID:20937152

  14. Retrieval Mode Distinguishes the Testing Effect from the Generation Effect

    ERIC Educational Resources Information Center

    Karpicke, Jeffrey D.; Zaromb, Franklin M.

    2010-01-01

    A series of four experiments examined the effects of generation vs. retrieval practice on subsequent retention. Subjects were first exposed to a list of target words. Then the subjects were shown the targets again intact for Read trials or they were shown fragments of the targets. Subjects in Generate conditions were told to complete the fragments…

  15. Query Processing in TREC-6.

    ERIC Educational Resources Information Center

    Rao, Ashwin; Lu, Allan; Meier, Ed; Ahmed, Salahuddin; Pliske, Daniel

    2000-01-01

    Discussion of query processing focuses on techniques developed by LEXIS-NEXIS for identifying key concepts, selecting synonyms and related terms, and detecting phrases that can be combined to increase recall and precision. Describes experiments in the ad hoc track of the sixth TREC (Text Retrieval Conference), including the use of ranking…

  16. Separate Mnemonic Effects of Retrieval Practice and Elaborative Encoding

    ERIC Educational Resources Information Center

    Karpicke, Jeffrey D.; Smith, Megan A.

    2012-01-01

    Does retrieval practice produce learning because it is an especially effective way to induce elaborative encoding? Four experiments examined this question. Subjects learned word pairs across alternating study and recall periods, and once an item was recalled it was dropped from further practice, repeatedly studied, or repeatedly retrieved on…

  17. Separate Mnemonic Effects of Retrieval Practice and Elaborative Encoding

    ERIC Educational Resources Information Center

    Karpicke, Jeffrey D.; Smith, Megan A.

    2012-01-01

    Does retrieval practice produce learning because it is an especially effective way to induce elaborative encoding? Four experiments examined this question. Subjects learned word pairs across alternating study and recall periods, and once an item was recalled it was dropped from further practice, repeatedly studied, or repeatedly retrieved on…

  18. Effects of Individualized Word Retrieval in Kindergarten Vocabulary Intervention

    ERIC Educational Resources Information Center

    Damhuis, Carmen M. P.; Segers, Eliane; Scheltinga, Femke; Verhoeven, Ludo

    2016-01-01

    We examined the effects of adaptive word retrieval intervention on a classroom vocabulary program on children's vocabulary acquisition in kindergarten. In the experimental condition, word retrieval was provided in a classroom vocabulary program, combining implicit and explicit vocabulary instructions. Children performed extra word retrieval…

  19. Effects of Individualized Word Retrieval in Kindergarten Vocabulary Intervention

    ERIC Educational Resources Information Center

    Damhuis, Carmen M. P.; Segers, Eliane; Scheltinga, Femke; Verhoeven, Ludo

    2016-01-01

    We examined the effects of adaptive word retrieval intervention on a classroom vocabulary program on children's vocabulary acquisition in kindergarten. In the experimental condition, word retrieval was provided in a classroom vocabulary program, combining implicit and explicit vocabulary instructions. Children performed extra word retrieval…

  20. A Perspective on the Measurement of Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Cooper, William S.

    1978-01-01

    Uses an historical analogy with Archimedes' problem concerning the volume of his king's golden crown to illustrate the evaluation problem for document and reference retrieval systems. Various methods that have been developed since 1950 to measure retrieval effectiveness are described, and utility measure formulas are provided. (JD)

  1. A Perspective on the Measurement of Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Cooper, William S.

    1978-01-01

    Uses an historical analogy with Archimedes' problem concerning the volume of his king's golden crown to illustrate the evaluation problem for document and reference retrieval systems. Various methods that have been developed since 1950 to measure retrieval effectiveness are described, and utility measure formulas are provided. (JD)

  2. Autonomic care platform for optimizing query performance

    PubMed Central

    2013-01-01

    Background As the amount of information in electronic health care systems increases, data operations get more complicated and time-consuming. Intensive Care platforms require a timely processing of data retrievals to guarantee the continuous display of recent data of patients. Physicians and nurses rely on this data for their decision making. Manual optimization of query executions has become difficult to handle due to the increased amount of queries across multiple sources. Hence, a more automated management is necessary to increase the performance of database queries. The autonomic computing paradigm promises an approach in which the system adapts itself and acts as self-managing entity, thereby limiting human interventions and taking actions. Despite the usage of autonomic control loops in network and software systems, this approach has not been applied so far for health information systems. Methods We extend the COSARA architecture, an infection surveillance and antibiotic management service platform for the Intensive Care Unit (ICU), with self-managed components to increase the performance of data retrievals. We used real-life ICU COSARA queries to analyse slow performance and measure the impact of optimizations. Each day more than 2 million COSARA queries are executed. Three control loops, which monitor the executions and take action, have been proposed: reactive, deliberative and reflective control loops. We focus on improvements of the execution time of microbiology queries directly related to the visual displays of patients’ data on the bedside screens. Results The results show that autonomic control loops are beneficial for the optimizations in the data executions in the ICU. The application of reactive control loop results in a reduction of 8.61% of the average execution time of microbiology results. The combined application of the reactive and deliberative control loop results in an average query time reduction of 10.92% and the combination of

  3. How Do Children Reformulate Their Search Queries?

    ERIC Educational Resources Information Center

    Rutter, Sophie; Ford, Nigel; Clough, Paul

    2015-01-01

    Introduction: This paper investigates techniques used by children in year 4 (age eight to nine) of a UK primary school to reformulate their queries, and how they use information retrieval systems to support query reformulation. Method: An in-depth study analysing the interactions of twelve children carrying out search tasks in a primary school…

  4. Fuzzy Query Processing Using Clustering Techniques.

    ERIC Educational Resources Information Center

    Kamel, M.; And Others

    1990-01-01

    Discusses the problem of processing fuzzy queries in databases and information retrieval systems and presents a prototype of a fuzzy query processing system for databases that is based on data clustering and uses Pascal programing language. Clustering schemes are explained, and the system architecture that uses natural language is described. (14…

  5. Flexible Phrase Based Query Handling Algorithms.

    ERIC Educational Resources Information Center

    Wilbur, W. John; Kim, Won

    2001-01-01

    Flexibility in query handling can be important if one types a search engine query that is misspelled, contains terms not in the database, or requires knowledge of a controlled vocabulary. Presents results of experiments that suggest the optimal form of similarity functions that are applicable to the task of phrase based retrieval to find either…

  6. Flexible Phrase Based Query Handling Algorithms.

    ERIC Educational Resources Information Center

    Wilbur, W. John; Kim, Won

    2001-01-01

    Flexibility in query handling can be important if one types a search engine query that is misspelled, contains terms not in the database, or requires knowledge of a controlled vocabulary. Presents results of experiments that suggest the optimal form of similarity functions that are applicable to the task of phrase based retrieval to find either…

  7. When Does Retrieval Induce Forgetting and when Does It Induce Facilitation? Implications for Retrieval Inhibition, Testing Effect, and Text Processing

    ERIC Educational Resources Information Center

    Chan, Jason C. K.

    2009-01-01

    Retrieval practice can enhance long-term retention of the tested material (the testing effect), but it can also impair later recall of the nontested material--a phenomenon known as retrieval-induced forgetting (Anderson, M. C., Bjork, R. A., & Bjork, E. L. (1994). "Remembering can cause forgetting: retrieval dynamics in long-term memory." "Journal…

  8. When Does Retrieval Induce Forgetting and when Does It Induce Facilitation? Implications for Retrieval Inhibition, Testing Effect, and Text Processing

    ERIC Educational Resources Information Center

    Chan, Jason C. K.

    2009-01-01

    Retrieval practice can enhance long-term retention of the tested material (the testing effect), but it can also impair later recall of the nontested material--a phenomenon known as retrieval-induced forgetting (Anderson, M. C., Bjork, R. A., & Bjork, E. L. (1994). "Remembering can cause forgetting: retrieval dynamics in long-term memory." "Journal…

  9. Timing matters: temporal dynamics of stress effects on memory retrieval.

    PubMed

    Schwabe, Lars; Wolf, Oliver T

    2014-09-01

    Stress may impair memory retrieval. This retrieval impairment has been attributed to the action of the stress hormone cortisol, which is released with a delay of several minutes after a stressful encounter. Hence, most studies tested memory retrieval 20-30 min after stress, when the stress-induced cortisol increase peaks. In the present experiment, we investigated whether retrieval impairments can also be found at later intervals after stress. To this end, participants learned a list of words on day 1. Twenty-four hours later, they were first exposed to a stressor or a nonstressful control manipulation and completed a recognition test for the words either immediately thereafter, 25 min later, or 90 min later. Our findings showed that stress did not impair memory retrieval when memory was tested immediately after the stressor, before cortisol levels were elevated. However, retrieval performance was impaired 25 min after stress, when cortisol levels peaked, as well as 90 min after the stressor, when cortisol levels had already returned to baseline. The retrieval impairment 90 min after stress appeared to be even stronger than the one after 25 min. These findings suggest that the detrimental effects of stress on retrieval performance may last longer than is usually assumed.

  10. Distance Between Sets as an Objective Measure of Retrieval Effectiveness

    ERIC Educational Resources Information Center

    Heine, M. H.

    1973-01-01

    The Marczewski-Steinhaus metric provides what appears to be an objective general measure of retrieval effectiveness within the framework of set theory and the theory of metric spaces. (19 references) (Author/SJ)

  11. The "Generality" Effect and the Retrieval Evaluation for Large Collections

    ERIC Educational Resources Information Center

    Salton, Gerard

    1972-01-01

    The role of the generality effect in retrieval system evaluation is assessed, and evaluation results are given for the comparison of several document collections of distinct size and generality in the areas of documentation and aerodynamics. (14 references) (Author)

  12. The "Generality" Effect and the Retrieval Evaluation for Large Collections

    ERIC Educational Resources Information Center

    Salton, Gerard

    1972-01-01

    The role of the generality effect in retrieval system evaluation is assessed, and evaluation results are given for the comparison of several document collections of distinct size and generality in the areas of documentation and aerodynamics. (14 references) (Author)

  13. Factors affecting the effectiveness of biomedical document indexing and retrieval based on terminologies.

    PubMed

    Dinh, Duy; Tamine, Lynda; Boubekeur, Fatiha

    2013-02-01

    The aim of this work is to evaluate a set of indexing and retrieval strategies based on the integration of several biomedical terminologies on the available TREC Genomics collections for an ad hoc information retrieval (IR) task. We propose a multi-terminology based concept extraction approach to selecting best concepts from free text by means of voting techniques. We instantiate this general approach on four terminologies (MeSH, SNOMED, ICD-10 and GO). We particularly focus on the effect of integrating terminologies into a biomedical IR process, and the utility of using voting techniques for combining the extracted concepts from each document in order to provide a list of unique concepts. Experimental studies conducted on the TREC Genomics collections show that our multi-terminology IR approach based on voting techniques are statistically significant compared to the baseline. For example, tested on the 2005 TREC Genomics collection, our multi-terminology based IR approach provides an improvement rate of +6.98% in terms of MAP (mean average precision) (p<0.05) compared to the baseline. In addition, our experimental results show that document expansion using preferred terms in combination with query expansion using terms from top ranked expanded documents improve the biomedical IR effectiveness. We have evaluated several voting models for combining concepts issued from multiple terminologies. Through this study, we presented many factors affecting the effectiveness of biomedical IR system including term weighting, query expansion, and document expansion models. The appropriate combination of those factors could be useful to improve the IR performance. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Structure of Domain Novice Users' Queries to a History Database.

    ERIC Educational Resources Information Center

    Cole, Charles; Leide, John E.; Nwakamma, Emeka; Beheshti, Jamshid; Large, Andrew

    2003-01-01

    Presents preliminary results from a study of an information need identification system for interactive information retrieval for undergraduates researching a history topic. Concludes that the query taxonomy must include levels of topic specificity because while general topic-based queries are inappropriate as query terms, more specific topic-based…

  15. Prospective memory: effects of divided attention on spontaneous retrieval.

    PubMed

    Harrison, Tyler L; Mullet, Hillary G; Whiffen, Katie N; Ousterhout, Hunter; Einstein, Gilles O

    2014-02-01

    We examined the effects of divided attention on the spontaneous retrieval of a prospective memory intention. Participants performed an ongoing lexical decision task with an embedded prospective memory demand, and also performed a divided-attention task during some segments of lexical decision trials. In all experiments, monitoring was highly discouraged, and we observed no evidence that participants engaged monitoring processes. In Experiment 1, performing a moderately demanding divided-attention task (a digit detection task) did not affect prospective memory performance. In Experiment 2, performing a more challenging divided-attention task (random number generation) impaired prospective memory. Experiment 3 showed that this impairment was eliminated when the prospective memory cue was perceptually salient. Taken together, the results indicate that spontaneous retrieval is not automatic and that challenging divided-attention tasks interfere with spontaneous retrieval and not with the execution of a retrieved intention.

  16. Development and empirical user-centered evaluation of semantically-based query recommendation for an electronic health record search engine.

    PubMed

    Hanauer, David A; Wu, Danny T Y; Yang, Lei; Mei, Qiaozhu; Murkowski-Steffy, Katherine B; Vydiswaran, V G Vinod; Zheng, Kai

    2017-03-01

    The utility of biomedical information retrieval environments can be severely limited when users lack expertise in constructing effective search queries. To address this issue, we developed a computer-based query recommendation algorithm that suggests semantically interchangeable terms based on an initial user-entered query. In this study, we assessed the value of this approach, which has broad applicability in biomedical information retrieval, by demonstrating its application as part of a search engine that facilitates retrieval of information from electronic health records (EHRs). The query recommendation algorithm utilizes MetaMap to identify medical concepts from search queries and indexed EHR documents. Synonym variants from UMLS are used to expand the concepts along with a synonym set curated from historical EHR search logs. The empirical study involved 33 clinicians and staff who evaluated the system through a set of simulated EHR search tasks. User acceptance was assessed using the widely used technology acceptance model. The search engine's performance was rated consistently higher with the query recommendation feature turned on vs. off. The relevance of computer-recommended search terms was also rated high, and in most cases the participants had not thought of these terms on their own. The questions on perceived usefulness and perceived ease of use received overwhelmingly positive responses. A vast majority of the participants wanted the query recommendation feature to be available to assist in their day-to-day EHR search tasks. Challenges persist for users to construct effective search queries when retrieving information from biomedical documents including those from EHRs. This study demonstrates that semantically-based query recommendation is a viable solution to addressing this challenge. Published by Elsevier Inc.

  17. The RETRIEVE trial: safety and effectiveness of the retrievable crux vena cava filter.

    PubMed

    Smouse, H Bob; Mendes, Robert; Bosiers, Marc; Van Ha, Thuong G; Crabtree, Tami

    2013-05-01

    To evaluate the safety and effectiveness of the Crux vena cava filter in patients at risk for pulmonary embolism (PE). The Crux Biomedical Evaluation of the Crux Inferior Vena Cava Filter System trial was an international prospective, multicenter, single-arm clinical trial in 125 patients implanted with the Crux filter between June 2010 and June 2011. Follow-up was 180 days after filter placement and 30 days after filter retrieval. The primary objective was to determine whether the clinical success rate was at least 80%. Clinical success was defined as technical success of deployment and freedom from definite PE, filter migration, and device-related adverse events requiring intervention. The clinical success rate was 96.0% (120 of 125), with a one-sided lower limit of the 95% confidence interval of 91.8%. The rate of technical success was 98.4% (123 of 125). There were three cases of definite PE (2.4%), two cases of deployment failure, and no cases of device migration, embolization, fracture, or tilting. Investigators observed nine cases of thrombus (all nonocclusive) in or near the filter (six during retrieval evaluation vena cavography, two during computed tomography [CT] scans for PE symptoms, and one during CT for cancer management) and 13 cases of deep vein thrombosis. Device retrieval was attempted at a mean of 84.6 days±57.6 (range, 6-190 d) after implantation and was successful for 98.1% of patients (53 of 54). All deaths (n = 14) were determined to be unrelated to the filter or PE. The Crux vena cava filter performed safely, with high rates of clinical, technical, and retrieval success. Copyright © 2013 SIR. Published by Elsevier Inc. All rights reserved.

  18. Semantics and the medical web: a review of barriers and breakthroughs in effective healthcare query.

    PubMed

    Lorence, Daniel P; Spink, Amanda

    2004-06-01

    This paper provides an overview of the research into current medical vocabularies and their impact on searching the Web for health information. The Web provides growing opportunities for laypersons to gain knowledge about specific health conditions, though research to date has been incomplete. Many studies have examined aspects of controlled medical vocabularies. Other studies have examined aspects of medical Web searching vocabularies. In this context, there is a growing need to examine more closely laypersons' Web queries using controlled medical vocabularies that were designed to serve the needs of medical professionals. It may be the case that the average consumer of Web health services is not able to use correct medical terminology, and may not be able to choose analogous or synonymous terms from a search result list. Our review suggests a growing need for studies to examine the current applicability of controlled medical vocabularies as well as alternatives to semantic query by Web search engine users.

  19. Hand movement effects on word learning and retrieval in adults.

    PubMed

    Ciantar, Jessica; Finch, Emma; Copland, David A

    2013-01-01

    The present study investigated the effect of performing an intentional non-meaningful hand movement on subsequent lexical acquisition and retrieval in healthy adults. Twenty-five right-handed healthy individuals were required to learn the names (2-syllable legal nonwords) for a series of unfamiliar objects. Participants also completed a familiar picture naming task to investigate the effects of the intentional non-meaningful movement on lexical retrieval. Results revealed that performing this hand movement immediately before linguistic tasks interfered with both new word learning and familiar picture naming when compared with no movement. These results extend previous findings of dual task interference effects in healthy individuals, suggesting that complex, non-meaningful, hand movements can also interfere with subsequent lexical acquisition and retrieval.

  20. Correction of Rayleigh Scattering Effects in Cloud Optical Thickness Retrievals

    NASA Technical Reports Server (NTRS)

    Wang, Meng-Hua; King, Michael D.

    1997-01-01

    We present results that demonstrate the effects of Rayleigh scattering on the 9 retrieval of cloud optical thickness at a visible wavelength (0.66 Am). The sensor-measured radiance at a visible wavelength (0.66 Am) is usually used to infer remotely the cloud optical thickness from aircraft or satellite instruments. For example, we find that without removing Rayleigh scattering effects, errors in the retrieved cloud optical thickness for a thin water cloud layer (T = 2.0) range from 15 to 60%, depending on solar zenith angle and viewing geometry. For an optically thick cloud (T = 10), on the other hand, errors can range from 10 to 60% for large solar zenith angles (0-60 deg) because of enhanced Rayleigh scattering. It is therefore particularly important to correct for Rayleigh scattering contributions to the reflected signal from a cloud layer both (1) for the case of thin clouds and (2) for large solar zenith angles and all clouds. On the basis of the single scattering approximation, we propose an iterative method for effectively removing Rayleigh scattering contributions from the measured radiance signal in cloud optical thickness retrievals. The proposed correction algorithm works very well and can easily be incorporated into any cloud retrieval algorithm. The Rayleigh correction method is applicable to cloud at any pressure, providing that the cloud top pressure is known to within +/- 100 bPa. With the Rayleigh correction the errors in retrieved cloud optical thickness are usually reduced to within 3%. In cases of both thin cloud layers and thick ,clouds with large solar zenith angles, the errors are usually reduced by a factor of about 2 to over 10. The Rayleigh correction algorithm has been tested with simulations for realistic cloud optical and microphysical properties with different solar and viewing geometries. We apply the Rayleigh correction algorithm to the cloud optical thickness retrievals from experimental data obtained during the Atlantic

  1. Correction of Rayleigh Scattering Effects in Cloud Optical Thickness Retrievals

    NASA Technical Reports Server (NTRS)

    Wang, Meng-Hua; King, Michael D.

    1997-01-01

    We present results that demonstrate the effects of Rayleigh scattering on the 9 retrieval of cloud optical thickness at a visible wavelength (0.66 Am). The sensor-measured radiance at a visible wavelength (0.66 Am) is usually used to infer remotely the cloud optical thickness from aircraft or satellite instruments. For example, we find that without removing Rayleigh scattering effects, errors in the retrieved cloud optical thickness for a thin water cloud layer (T = 2.0) range from 15 to 60%, depending on solar zenith angle and viewing geometry. For an optically thick cloud (T = 10), on the other hand, errors can range from 10 to 60% for large solar zenith angles (0-60 deg) because of enhanced Rayleigh scattering. It is therefore particularly important to correct for Rayleigh scattering contributions to the reflected signal from a cloud layer both (1) for the case of thin clouds and (2) for large solar zenith angles and all clouds. On the basis of the single scattering approximation, we propose an iterative method for effectively removing Rayleigh scattering contributions from the measured radiance signal in cloud optical thickness retrievals. The proposed correction algorithm works very well and can easily be incorporated into any cloud retrieval algorithm. The Rayleigh correction method is applicable to cloud at any pressure, providing that the cloud top pressure is known to within +/- 100 bPa. With the Rayleigh correction the errors in retrieved cloud optical thickness are usually reduced to within 3%. In cases of both thin cloud layers and thick ,clouds with large solar zenith angles, the errors are usually reduced by a factor of about 2 to over 10. The Rayleigh correction algorithm has been tested with simulations for realistic cloud optical and microphysical properties with different solar and viewing geometries. We apply the Rayleigh correction algorithm to the cloud optical thickness retrievals from experimental data obtained during the Atlantic

  2. QCS : a system for querying, clustering, and summarizing documents.

    SciTech Connect

    Dunlavy, Daniel M.

    2006-08-01

    Information retrieval systems consist of many complicated components. Research and development of such systems is often hampered by the difficulty in evaluating how each particular component would behave across multiple systems. We present a novel hybrid information retrieval system--the Query, Cluster, Summarize (QCS) system--which is portable, modular, and permits experimentation with different instantiations of each of the constituent text analysis components. Most importantly, the combination of the three types of components in the QCS design improves retrievals by providing users more focused information organized by topic. We demonstrate the improved performance by a series of experiments using standard test sets from the Document Understanding Conferences (DUC) along with the best known automatic metric for summarization system evaluation, ROUGE. Although the DUC data and evaluations were originally designed to test multidocument summarization, we developed a framework to extend it to the task of evaluation for each of the three components: query, clustering, and summarization. Under this framework, we then demonstrate that the QCS system (end-to-end) achieves performance as good as or better than the best summarization engines. Given a query, QCS retrieves relevant documents, separates the retrieved documents into topic clusters, and creates a single summary for each cluster. In the current implementation, Latent Semantic Indexing is used for retrieval, generalized spherical k-means is used for the document clustering, and a method coupling sentence ''trimming'', and a hidden Markov model, followed by a pivoted QR decomposition, is used to create a single extract summary for each cluster. The user interface is designed to provide access to detailed information in a compact and useful format. Our system demonstrates the feasibility of assembling an effective IR system from existing software libraries, the usefulness of the modularity of the design, and the

  3. QCS: a system for querying, clustering and summarizing documents.

    SciTech Connect

    Dunlavy, Daniel M.; Schlesinger, Judith D. (Center for Computing Sciences, Bowie, MD); O'Leary, Dianne P.; Conroy, John M.

    2006-10-01

    Information retrieval systems consist of many complicated components. Research and development of such systems is often hampered by the difficulty in evaluating how each particular component would behave across multiple systems. We present a novel hybrid information retrieval system--the Query, Cluster, Summarize (QCS) system--which is portable, modular, and permits experimentation with different instantiations of each of the constituent text analysis components. Most importantly, the combination of the three types of components in the QCS design improves retrievals by providing users more focused information organized by topic. We demonstrate the improved performance by a series of experiments using standard test sets from the Document Understanding Conferences (DUC) along with the best known automatic metric for summarization system evaluation, ROUGE. Although the DUC data and evaluations were originally designed to test multidocument summarization, we developed a framework to extend it to the task of evaluation for each of the three components: query, clustering, and summarization. Under this framework, we then demonstrate that the QCS system (end-to-end) achieves performance as good as or better than the best summarization engines. Given a query, QCS retrieves relevant documents, separates the retrieved documents into topic clusters, and creates a single summary for each cluster. In the current implementation, Latent Semantic Indexing is used for retrieval, generalized spherical k-means is used for the document clustering, and a method coupling sentence 'trimming', and a hidden Markov model, followed by a pivoted QR decomposition, is used to create a single extract summary for each cluster. The user interface is designed to provide access to detailed information in a compact and useful format. Our system demonstrates the feasibility of assembling an effective IR system from existing software libraries, the usefulness of the modularity of the design, and the

  4. TQuery: a context-sensitive temporal query language.

    PubMed

    Kahn, M G; Tu, S; Fagan, L M

    1991-10-01

    Users of electronic medical databases request pertinent information by recasting their clinical questions into a formal database query language. Because the query language is the user's only access to the data, the query language must be powerful enough to enable users to express their data requirements. However, a competing need is for the query language to be restrictive enough so that queries can have unambiguous semantics and the query processor can generate correct answers. We describe a query language, called TQuery , that was designed specifically to formulate database queries that are dependent on temporal and contextual relationships. TQuery specifications express contextual constraints without the need to explicitly reference calendar dates. TQuery is the database query language used to retrieve patient data from an object-oriented electronic patient medical-record system called the temporal network (TNET). TNET and TQuery were developed to support the real-time temporal reasoning and representation needs of a LISP workstation-based medical expert system.

  5. Secure Nearest Neighbor Query on Crowd-Sensing Data

    PubMed Central

    Cheng, Ke; Wang, Liangmin; Zhong, Hong

    2016-01-01

    Nearest neighbor queries are fundamental in location-based services, and secure nearest neighbor queries mainly focus on how to securely and quickly retrieve the nearest neighbor in the outsourced cloud server. However, the previous big data system structure has changed because of the crowd-sensing data. On the one hand, sensing data terminals as the data owner are numerous and mistrustful, while, on the other hand, in most cases, the terminals find it difficult to finish many safety operation due to computation and storage capability constraints. In light of they Multi Owners and Multi Users (MOMU) situation in the crowd-sensing data cloud environment, this paper presents a secure nearest neighbor query scheme based on the proxy server architecture, which is constructed by protocols of secure two-party computation and secure Voronoi diagram algorithm. It not only preserves the data confidentiality and query privacy but also effectively resists the collusion between the cloud server and the data owners or users. Finally, extensive theoretical and experimental evaluations are presented to show that our proposed scheme achieves a superior balance between the security and query performance compared to other schemes. PMID:27669253

  6. Secure Nearest Neighbor Query on Crowd-Sensing Data.

    PubMed

    Cheng, Ke; Wang, Liangmin; Zhong, Hong

    2016-09-22

    Nearest neighbor queries are fundamental in location-based services, and secure nearest neighbor queries mainly focus on how to securely and quickly retrieve the nearest neighbor in the outsourced cloud server. However, the previous big data system structure has changed because of the crowd-sensing data. On the one hand, sensing data terminals as the data owner are numerous and mistrustful, while, on the other hand, in most cases, the terminals find it difficult to finish many safety operation due to computation and storage capability constraints. In light of they Multi Owners and Multi Users (MOMU) situation in the crowd-sensing data cloud environment, this paper presents a secure nearest neighbor query scheme based on the proxy server architecture, which is constructed by protocols of secure two-party computation and secure Voronoi diagram algorithm. It not only preserves the data confidentiality and query privacy but also effectively resists the collusion between the cloud server and the data owners or users. Finally, extensive theoretical and experimental evaluations are presented to show that our proposed scheme achieves a superior balance between the security and query performance compared to other schemes.

  7. Multiview Locally Linear Embedding for Effective Medical Image Retrieval

    PubMed Central

    Shen, Hualei; Tao, Dacheng; Ma, Dianfu

    2013-01-01

    Content-based medical image retrieval continues to gain attention for its potential to assist radiological image interpretation and decision making. Many approaches have been proposed to improve the performance of medical image retrieval system, among which visual features such as SIFT, LBP, and intensity histogram play a critical role. Typically, these features are concatenated into a long vector to represent medical images, and thus traditional dimension reduction techniques such as locally linear embedding (LLE), principal component analysis (PCA), or laplacian eigenmaps (LE) can be employed to reduce the “curse of dimensionality”. Though these approaches show promising performance for medical image retrieval, the feature-concatenating method ignores the fact that different features have distinct physical meanings. In this paper, we propose a new method called multiview locally linear embedding (MLLE) for medical image retrieval. Following the patch alignment framework, MLLE preserves the geometric structure of the local patch in each feature space according to the LLE criterion. To explore complementary properties among a range of features, MLLE assigns different weights to local patches from different feature spaces. Finally, MLLE employs global coordinate alignment and alternating optimization techniques to learn a smooth low-dimensional embedding from different features. To justify the effectiveness of MLLE for medical image retrieval, we compare it with conventional spectral embedding methods. We conduct experiments on a subset of the IRMA medical image data set. Evaluation results show that MLLE outperforms state-of-the-art dimension reduction methods. PMID:24349277

  8. The Effects of Alcohol on the Speed of Memory Retrieval.

    ERIC Educational Resources Information Center

    Stempel, Jennifer J.; And Others

    Recent research has clearly indicated that intoxication with alcohol impairs memory. The present study investigated the effects of alcohol on retrieval from long-term memory by using a set of cognitive decision tasks. Subjects (N=24) were female college students in good health not taking oral contraceptives. Subjects were administered 0 or 1.0…

  9. Age Differences in Recollection: Specificity Effects at Retrieval

    ERIC Educational Resources Information Center

    Luo, Lin; Craik, Fergus I. M.

    2009-01-01

    Three experiments were conducted to examine the effect of specificity at retrieval on the size of age differences in recollection. Participants encoded words in different contexts and were given recognition tests. Some of the test lists were constructed so that participants had to recollect specific aspects of the initial encoding events, whereas…

  10. Information Retrieval Techniques.

    ERIC Educational Resources Information Center

    Kantor, Paul B.

    1994-01-01

    Identifies current trends in the automation of indexing, of information retrieval, and of interaction between the system and the users. Topics discussed include location, navigation, and indexing; digital libraries; matching documents to queries; weight of concepts; query structure, including fuzzy sets; algorithms; stemming; clustering; users'…

  11. Hybrid ontology for semantic information retrieval model using keyword matching indexing system.

    PubMed

    Uthayan, K R; Mala, G S Anandha

    2015-01-01

    Ontology is the process of growth and elucidation of concepts of an information domain being common for a group of users. Establishing ontology into information retrieval is a normal method to develop searching effects of relevant information users require. Keywords matching process with historical or information domain is significant in recent calculations for assisting the best match for specific input queries. This research presents a better querying mechanism for information retrieval which integrates the ontology queries with keyword search. The ontology-based query is changed into a primary order to predicate logic uncertainty which is used for routing the query to the appropriate servers. Matching algorithms characterize warm area of researches in computer science and artificial intelligence. In text matching, it is more dependable to study semantics model and query for conditions of semantic matching. This research develops the semantic matching results between input queries and information in ontology field. The contributed algorithm is a hybrid method that is based on matching extracted instances from the queries and information field. The queries and information domain is focused on semantic matching, to discover the best match and to progress the executive process. In conclusion, the hybrid ontology in semantic web is sufficient to retrieve the documents when compared to standard ontology.

  12. Toward privacy-preserving JPEG image retrieval

    NASA Astrophysics Data System (ADS)

    Cheng, Hang; Wang, Jingyue; Wang, Meiqing; Zhong, Shangping

    2017-07-01

    This paper proposes a privacy-preserving retrieval scheme for JPEG images based on local variance. Three parties are involved in the scheme: the content owner, the server, and the authorized user. The content owner encrypts JPEG images for privacy protection by jointly using permutation cipher and stream cipher, and then, the encrypted versions are uploaded to the server. With an encrypted query image provided by an authorized user, the server may extract blockwise local variances in different directions without knowing the plaintext content. After that, it can calculate the similarity between the encrypted query image and each encrypted database image by a local variance-based feature comparison mechanism. The authorized user with the encryption key can decrypt the returned encrypted images with plaintext content similar to the query image. The experimental results show that the proposed scheme not only provides effective privacy-preserving retrieval service but also ensures both format compliance and file size preservation for encrypted JPEG images.

  13. An Evaluation of the Applicability of Ranking Algorithms to Improve the Effectiveness of Full-Text Retrieval. I. On the Effectiveness of Full-Text Retrieval.

    ERIC Educational Resources Information Center

    Ro, Jung Soon

    1988-01-01

    A comparison of the effectiveness of information retrieval based on full-text documents with retrieval based on paragraphs, abstracts, or controlled vocabularies was accomplished using a subset of journal articles with nine search questions. It was found that full-text retrieval achieved significantly higher recall and lower precision than did the…

  14. Federated ontology-based queries over cancer data

    PubMed Central

    2012-01-01

    Background Personalised medicine provides patients with treatments that are specific to their genetic profiles. It requires efficient data sharing of disparate data types across a variety of scientific disciplines, such as molecular biology, pathology, radiology and clinical practice. Personalised medicine aims to offer the safest and most effective therapeutic strategy based on the gene variations of each subject. In particular, this is valid in oncology, where knowledge about genetic mutations has already led to new therapies. Current molecular biology techniques (microarrays, proteomics, epigenetic technology and improved DNA sequencing technology) enable better characterisation of cancer tumours. The vast amounts of data, however, coupled with the use of different terms - or semantic heterogeneity - in each discipline makes the retrieval and integration of information difficult. Results Existing software infrastructures for data-sharing in the cancer domain, such as caGrid, support access to distributed information. caGrid follows a service-oriented model-driven architecture. Each data source in caGrid is associated with metadata at increasing levels of abstraction, including syntactic, structural, reference and domain metadata. The domain metadata consists of ontology-based annotations associated with the structural information of each data source. However, caGrid's current querying functionality is given at the structural metadata level, without capitalising on the ontology-based annotations. This paper presents the design of and theoretical foundations for distributed ontology-based queries over cancer research data. Concept-based queries are reformulated to the target query language, where join conditions between multiple data sources are found by exploiting the semantic annotations. The system has been implemented, as a proof of concept, over the caGrid infrastructure. The approach is applicable to other model-driven architectures. A graphical user

  15. Generalized method for retrieving effective parameters of anisotropic metamaterials.

    PubMed

    Castanié, A; Mercier, J-F; Félix, S; Maurel, A

    2014-12-01

    Electromagnetic or acoustic metamaterials can be described in terms of equivalent effective, in general anisotropic, media and several techniques exist to determine the effective permeability and permittivity (or effective mass density and bulk modulus in the context of acoustics). Among these techniques, retrieval methods use the measured reflection and transmission coefficients (or scattering coefficients) for waves incident on a metamaterial slab containing few unit cells. Until now, anisotropic effective slabs have been considered in the literature but they are limited to the case where one of the axes of anisotropy is aligned with the slab interface. We propose an extension to arbitrary orientations of the principal axes of anisotropy and oblique incidence. The retrieval method is illustrated in the electromagnetic case for layered media, and in the acoustic case for array of tilted elliptical particles.

  16. A drifting GPS buoy for retrieving effective riverbed bathymetry

    NASA Astrophysics Data System (ADS)

    Hostache, R.; Matgen, P.; Giustarini, L.; Teferle, F. N.; Tailliez, C.; Iffly, J.-F.; Corato, G.

    2015-01-01

    Spatially distributed riverbed bathymetry information are rarely available but mandatory for accurate hydrodynamic modeling. This study aims at evaluating the potential of the Global Navigation Satellite System (GNSS), like for instance Global Positioning System (GPS), for retrieving such data. Drifting buoys equipped with navigation systems such as GPS enable the quasi-continuous measurement of water surface elevation, from virtually any point in the world. The present study investigates the potential of assimilating GNSS-derived water surface elevation measurements into hydraulic models in order to retrieve effective riverbed bathymetry. First tests with a GPS dual-frequency receiver show that the root mean squared error (RMSE) on the elevation measurement equals 30 cm provided that a differential post processing is performed. Next, synthetic observations of a drifting buoy were generated assuming a 30 cm average error of Water Surface Elevation (WSE) measurements. By assimilating the synthetic observation into a 1D-Hydrodynamic model, we show that the riverbed bathymetry can be retrieved with an accuracy of 36 cm. Moreover, the WSEs simulated by the hydrodynamic model using the retrieved bathymetry are in good agreement with the synthetic "truth", exhibiting an RMSE of 27 cm.

  17. Cortisol effects on autobiographic memory retrieval in PTSD: an analysis of word valence and time until retrieval.

    PubMed

    Wingenfeld, Katja; Driessen, Martin; Schlosser, Nicole; Terfehr, Kirsten; Carvalho Fernando, Silvia; Wolf, Oliver Tobias

    2013-09-01

    In healthy participants, cortisol administration has been found to impair autobiographic memory retrieval. We recently reported that administration of 10 mg of hydrocortisone had enhancing effects on autobiographical memory retrieval, i.e. more specific memory retrieval, in patients with posttraumatic stress disorder (PTSD), while in healthy controls the impairing effects were replicated. We here report a re-analysis of these data with respect to cue-word valence and retrieval time. In a placebo-controlled cross-over study, 43 patients with PTSD and 43 age- and sex-matched healthy controls received either placebo or hydrocortisone orally before the autobiographical memory test was performed. We found that the effects of cortisol on memory retrieval depended on cue-word valence and group (significant interaction effects of drug by group and drug by valence by group). The enhancing effect of cortisol on memory retrieval in PTSD seemed to be relatively independent of cue-word valence, while in the control group the impairing effects of cortisol were only seen in response to neutral cue-words. The second result of the study was that in patients as well as in controls, cortisol administration led to faster memory retrieval compared to placebo. This was seen in response to positive and (to lesser extend) to neutral cue-words, but not in response to negative cue-words. Our findings illustrate that the opposing effects of cortisol on autobiographical memory retrieval in PTSD patients and controls are further modulated by the emotionality of the cue-words.

  18. Improving multimedia retrieval with a video OCR

    NASA Astrophysics Data System (ADS)

    Das, Dipanjan; Chen, Datong; Hauptmann, Alexander G.

    2008-01-01

    We present a set of experiments with a video OCR system (VOCR) tailored for video information retrieval and establish its importance in multimedia search in general and for some specific queries in particular. The system, inspired by an existing work on text detection and recognition in images, has been developed using techniques involving detailed analysis of video frames producing candidate text regions. The text regions are then binarized and sent to a commercial OCR resulting in ASCII text, that is finally used to create search indexes. The system is evaluated using the TRECVID data. We compare the system's performance from an information retrieval perspective with another VOCR developed using multi-frame integration and empirically demonstrate that deep analysis on individual video frames result in better video retrieval. We also evaluate the effect of various textual sources on multimedia retrieval by combining the VOCR outputs with automatic speech recognition (ASR) transcripts. For general search queries, the VOCR system coupled with ASR sources outperforms the other system by a very large extent. For search queries that involve named entities, especially people names, the VOCR system even outperforms speech transcripts, demonstrating that source selection for particular query types is extremely essential.

  19. Use of controlled vocabularies to improve biomedical information retrieval tasks.

    PubMed

    Pasche, Emilie; Gobeill, Julien; Vishnyakova, Dina; Ruch, Patrick; Lovis, Christian

    2013-01-01

    The high heterogeneity of biomedical vocabulary is a major obstacle for information retrieval in large biomedical collections. Therefore, using biomedical controlled vocabularies is crucial for managing these contents. We investigate the impact of query expansion based on controlled vocabularies to improve the effectiveness of two search engines. Our strategy relies on the enrichment of users' queries with additional terms, directly derived from such vocabularies applied to infectious diseases and chemical patents. We observed that query expansion based on pathogen names resulted in improvements of the top-precision of our first search engine, while the normalization of diseases degraded the top-precision. The expansion of chemical entities, which was performed on the second search engine, positively affected the mean average precision. We have shown that query expansion of some types of biomedical entities has a great potential to improve search effectiveness; therefore a fine-tuning of query expansion strategies could help improving the performances of search engines.

  20. The recency effect: implicit learning with explicit retrieval?

    PubMed

    Baddeley, A D; Hitch, G

    1993-03-01

    The recency effect in free recall features prominently in 1960s' theorizing about short-term memory, but has since been largely ignored. We argue that this stems from a preoccupation with the role of recency in the concept of primary memory and the neglect of its role in a broader working-memory framework. It is suggested that the recency effect reflects the application of an explicit retrieval strategy to the residue of implicit learning within a range of cognitive systems. When retrieved implicitly, the same residue is assumed to form the basis of priming effects. The various criteria for implicit learning described by Tulving and Schacter (1990) are successfully applied to the recency effect, and a retrieval process is outlined that can account for both long- and short-term recency effects. It is suggested that a framework combining recency, priming, and implicit learning provides a basis for understanding one of the most important features of cognition and memory, namely, that of maintaining orientation in time and place.

  1. Knowledge Query Language (KQL)

    DTIC Science & Technology

    2016-02-12

    making portability of the queries or query-dependent algorithms difficult. This report introduces an ontological declarative approach that is...Expressions using the ontology implemented in a knowledge registry, and returning query results with provenance information...OF CONTENTS Page Executive Summary iii Acknowledgments v List of Figures ix 1. INTRODUCTION 1 2. DETAILED DESCRIPTION 3 2.1 Registry Ontology 6

  2. Knowledge Query Language (KQL)

    DTIC Science & Technology

    2016-02-01

    portability of the queries or query-dependent algorithms difficult. This report introduces an ontological declarative approach that is independent...Expressions using the ontology implemented in a knowledge registry, and returning query results with provenance information...Page Executive Summary iii Acknowledgments v List of Figures ix 1. INTRODUCTION 1 2. DETAILED DESCRIPTION 3 2.1 Registry Ontology 6 2.2

  3. A query suggestion workflow for life science IR-systems.

    PubMed

    Esch, Maria; Chen, Jinbo; Weise, Stephan; Hassani-Pak, Keywan; Scholz, Uwe; Lange, Matthias

    2014-06-13

    Information Retrieval (IR) plays a central role in the exploration and interpretation of integrated biological datasets that represent the heterogeneous ecosystem of life sciences. Here, keyword based query systems are popular user interfaces. In turn, to a large extend, the used query phrases determine the quality of the search result and the effort a scientist has to invest for query refinement. In this context, computer aided query expansion and suggestion is one of the most challenging tasks for life science information systems. Existing query front-ends support aspects like spelling correction, query refinement or query expansion. However, the majority of the front-ends only make limited use of enhanced IR algorithms to implement comprehensive and computer aided query refinement workflows. In this work, we present the design of a multi-stage query suggestion workflow and its implementation in the life science IR system LAILAPS. The presented workflow includes enhanced tokenisation, word breaking, spelling correction, query expansion and query suggestion ranking. A spelling correction benchmark with 5,401 queries and manually selected use cases for query expansion demonstrate the performance of the implemented workflow and its advantages compared with state-of-the-art systems.

  4. An integrated content and metadata based retrieval system for art.

    PubMed

    Lewis, Paul H; Martinez, Kirk; Abas, Fazly Salleh; Fauzi, Mohammad Faizal Ahmad; Chan, Stephen C Y; Addis, Matthew J; Boniface, Mike J; Grimwood, Paul; Stevenson, Alison; Lahanier, Christian; Stevenson, James

    2004-03-01

    A new approach to image retrieval is presented in the domain of museum and gallery image collections. Specialist algorithms, developed to address specific retrieval tasks, are combined with more conventional content and metadata retrieval approaches, and implemented within a distributed architecture to provide cross-collection searching and navigation in a seamless way. External systems can access the different collections using interoperability protocols and open standards, which were extended to accommodate content based as well as text based retrieval paradigms. After a brief overview of the complete system, we describe the novel design and evaluation of some of the specialist image analysis algorithms including a method for image retrieval based on sub-image queries, retrievals based on very low quality images and retrieval using canvas crack patterns. We show how effective retrieval results can be achieved by real end-users consisting of major museums and galleries, accessing the distributed but integrated digital collections.

  5. Functions of a Man-Machine Interactive Information Retrieval System

    DTIC Science & Technology

    An effective man-machine interactive retrieval system is not achieved by simply placing a terminal on each end of an existing machine retrieval...many of these needs was developed and tested. The objective of the development of this system, BROWSER, was to investigate the effectiveness of a free...form query with a combinatorial search algorithm and the effectiveness of various techniques and components to facilitate online browsing.

  6. Interactive ultrasound image retrieval using magnitude frequency spectrum

    NASA Astrophysics Data System (ADS)

    Son, Jae Gon; Kim, Nam Chul; Chun, Young Deok; Park, Jun Hyo; Bae, Jun Ik

    2003-05-01

    An efficient algorithm is proposed for interactive ultrasound image retrieval using magnitude frequency spectrum (MFS). The interactive retrieval is especially intended to be useful for training an intern to diagnose with ultrasound images. In the retrieval process, information on which are relevant to a query image among object images retrieved in the previous iteration is fed back by user interaction. In order to improve discrimination between a query image and each of object images in a database (DB) by using the MFS, which is powerful for ultrasound image retrieval, we incorporate feature vector normalization and root filtering in feature extraction. To effectively integrate the feedback information, we use a feedback scheme based on Rocchio equation, where the feature of a query image is replaced with the weighted average of the feature of a query image and those of object images. Experimental results for real ultrasound images show that while yielding a precision of about 75% at a recall of about 8% in the initial retrieval, the interactive procedure yields a great performance improvement, that is, a precision of about 95% in the third iteration.

  7. Design and Implementation of Automatic Indexing for Information Retrieval with Arabic Documents.

    ERIC Educational Resources Information Center

    Hmeidi, Ismail; Kanaan, Ghassan; Evens, Martha

    1997-01-01

    Describes automatic information retrieval system designed and built to handle Arabic data. Discusses cost-effectiveness of automatic indexing. Compares retrieval results using words as index terms versus stems and roots. Includes 19 tables; 60 queries using full words and relevance judgments are appended. (JAK)

  8. Automatic Dictionary Construction; Part II of Scientific Report No. ISR-18, Information Storage and Retrieval...

    ERIC Educational Resources Information Center

    Cornell Univ., Ithaca, NY. Dept. of Computer Science.

    Part Two of the eighteenth report on Salton's Magical Automatic Retriever of Texts (SMART) project is composed of three papers: The first: "The Effect of Common Words and Synonyms on Retrieval Performance" by D. Bergmark discloses that removal of common words from the query and document vectors significantly increases precision and that…

  9. Individual Differences in the Effects of Retrieval from Long-Term Memory

    ERIC Educational Resources Information Center

    Brewer, Gene A.; Unsworth, Nash

    2012-01-01

    The current study examined individual differences in the effects of retrieval from long-term memory (i.e., the testing effect). The effects of retrieving from memory make tested information more accessible for future retrieval attempts. Despite the broad applied ramifications of such a potent memorization technique there is a paucity of research…

  10. Individual Differences in the Effects of Retrieval from Long-Term Memory

    ERIC Educational Resources Information Center

    Brewer, Gene A.; Unsworth, Nash

    2012-01-01

    The current study examined individual differences in the effects of retrieval from long-term memory (i.e., the testing effect). The effects of retrieving from memory make tested information more accessible for future retrieval attempts. Despite the broad applied ramifications of such a potent memorization technique there is a paucity of research…

  11. Textual query of personal photos facilitated by large-scale web data.

    PubMed

    Liu, Yiming; Xu, Dong; Tsang, Ivor Wai-Hung; Luo, Jiebo

    2011-05-01

    The rapid popularization of digital cameras and mobile phone cameras has led to an explosive growth of personal photo collections by consumers. In this paper, we present a real-time textual query-based personal photo retrieval system by leveraging millions of Web images and their associated rich textual descriptions (captions, categories, etc.). After a user provides a textual query (e.g., “water”), our system exploits the inverted file to automatically find the positive Web images that are related to the textual query “water” as well as the negative Web images that are irrelevant to the textual query. Based on these automatically retrieved relevant and irrelevant Web images, we employ three simple but effective classification methods, k-Nearest Neighbor (kNN), decision stumps, and linear SVM, to rank personal photos. To further improve the photo retrieval performance, we propose two relevance feedback methods via cross-domain learning, which effectively utilize both the Web images and personal images. In particular, our proposed crossdomain learning methods can learn robust classifiers with only a very limited amount of labeled personal photos from the user by leveraging the prelearned linear SVM classifiers in real time. We further propose an incremental cross-domain learning method in order to significantly accelerate the relevance feedback process on large consumer photo databases. Extensive experiments on two consumer photo data sets demonstrate the effectiveness and efficiency of our system, which is also inherently not limited by any predefined lexicon.

  12. An Ensemble Approach for Expanding Queries

    DTIC Science & Technology

    2012-11-01

    Rindflesch T, Nebeker J. Synonym, Topic Model and Predicate-Based Query Expansion for Retrieving Clinical Documents. AMIA 2012 Annual Symposium; Nov. 5...arterial branching predications asserted in cardiac catheterization reports. Proc AMIA Annual Symposium; 2000 2000. 7. Divita G, Zeng-Trietler Q

  13. The StarView intelligent query mechanism

    NASA Technical Reports Server (NTRS)

    Semmel, R. D.; Silberberg, D. P.

    1993-01-01

    The StarView interface is being developed to facilitate the retrieval of scientific and engineering data produced by the Hubble Space Telescope. While predefined screens in the interface can be used to specify many common requests, ad hoc requests require a dynamic query formulation capability. Unfortunately, logical level knowledge is too sparse to support this capability. In particular, essential formulation knowledge is lost when the domain of interest is mapped to a set of database relation schemas. Thus, a system known as QUICK has been developed that uses conceptual design knowledge to facilitate query formulation. By heuristically determining strongly associated objects at the conceptual level, QUICK is able to formulate semantically reasonable queries in response to high-level requests that specify only attributes of interest. Moreover, by exploiting constraint knowledge in the conceptual design, QUICK assures that queries are formulated quickly and will execute efficiently.

  14. Effects of Divided Attention at Retrieval on Conceptual Implicit Memory

    PubMed Central

    Prull, Matthew W.; Lawless, Courtney; Marshall, Helen M.; Sherman, Annabella T. K.

    2016-01-01

    This study investigated whether conceptual implicit memory is sensitive to process-specific interference at the time of retrieval. Participants performed the implicit memory test of category exemplar generation (CEG; Experiments 1 and 3), or the matched explicit memory test of category-cued recall (Experiment 2), both of which are conceptually driven memory tasks, under one of two divided attention (DA) conditions in which participants simultaneously performed a distracting task. The distracting task was either syllable judgments (dissimilar processes), or semantic judgments (similar processes) on unrelated words. Compared to full attention (FA) in which no distracting task was performed, DA had no effect on CEG priming overall, but reduced category-cued recall similarly regardless of distractor task. Analyses of distractor task performance also revealed differences between implicit and explicit memory retrieval. The evidence suggests that, whereas explicit memory retrieval requires attentional resources and is disrupted by semantic and phonological distracting tasks, conceptual implicit memory is automatic and unaffected even when distractor and memory tasks involve similar processes. PMID:26834678

  15. Effects of Divided Attention at Retrieval on Conceptual Implicit Memory.

    PubMed

    Prull, Matthew W; Lawless, Courtney; Marshall, Helen M; Sherman, Annabella T K

    2016-01-01

    This study investigated whether conceptual implicit memory is sensitive to process-specific interference at the time of retrieval. Participants performed the implicit memory test of category exemplar generation (CEG; Experiments 1 and 3), or the matched explicit memory test of category-cued recall (Experiment 2), both of which are conceptually driven memory tasks, under one of two divided attention (DA) conditions in which participants simultaneously performed a distracting task. The distracting task was either syllable judgments (dissimilar processes), or semantic judgments (similar processes) on unrelated words. Compared to full attention (FA) in which no distracting task was performed, DA had no effect on CEG priming overall, but reduced category-cued recall similarly regardless of distractor task. Analyses of distractor task performance also revealed differences between implicit and explicit memory retrieval. The evidence suggests that, whereas explicit memory retrieval requires attentional resources and is disrupted by semantic and phonological distracting tasks, conceptual implicit memory is automatic and unaffected even when distractor and memory tasks involve similar processes.

  16. Effects of immune activation on the retrieval of spatial memory.

    PubMed

    Huang, Zhen-Bo; Wang, Hao; Rao, Xiu-Rong; Liang, Tao; Xu, Jing; Cai, Xiang-Sheng; Sheng, Guo-Qing

    2010-10-01

    It has been shown that there are extensive interactions between the central nervous system and the immune system. The present study focused on the effects of lipopolysaccharide (LPS) on memory retrieval, to explore the interaction between immune activation and memory. C57BL/6J mice (8 weeks old) were first trained in the Morris water maze to reach asymptotic performance. Then mice were tested 24 h after the last training session and LPS was administered (1.25 mg/kg, i.p.) 4 h prior to the testing. The retrieval of spatial memory was tested by probe trial, and the time spent in the target quadrant and the number of platform location crosses were recorded. ELISA was performed to detect interleukin-1β (IL-1β) protein level in the hippocampus of mice tested in the water maze. Although LPS induced overt sickness behavior and a significant increase in the level of IL-1β in the hippocampus of mice, there was no significant difference in the time spent in the target quadrant or in the number of platform location crosses between LPS-treated and control groups in the probe trial testing. Immune activation induced by LPS does not impair the retrieval of spatial memory.

  17. A semantic medical multimedia retrieval approach using ontology information hiding.

    PubMed

    Guo, Kehua; Zhang, Shigeng

    2013-01-01

    Searching useful information from unstructured medical multimedia data has been a difficult problem in information retrieval. This paper reports an effective semantic medical multimedia retrieval approach which can reflect the users' query intent. Firstly, semantic annotations will be given to the multimedia documents in the medical multimedia database. Secondly, the ontology that represented semantic information will be hidden in the head of the multimedia documents. The main innovations of this approach are cross-type retrieval support and semantic information preservation. Experimental results indicate a good precision and efficiency of our approach for medical multimedia retrieval in comparison with some traditional approaches.

  18. A Semantic Medical Multimedia Retrieval Approach Using Ontology Information Hiding

    PubMed Central

    Guo, Kehua; Zhang, Shigeng

    2013-01-01

    Searching useful information from unstructured medical multimedia data has been a difficult problem in information retrieval. This paper reports an effective semantic medical multimedia retrieval approach which can reflect the users' query intent. Firstly, semantic annotations will be given to the multimedia documents in the medical multimedia database. Secondly, the ontology that represented semantic information will be hidden in the head of the multimedia documents. The main innovations of this approach are cross-type retrieval support and semantic information preservation. Experimental results indicate a good precision and efficiency of our approach for medical multimedia retrieval in comparison with some traditional approaches. PMID:24082915

  19. A comparison of retrieval effectiveness for three methods of indexing medical literature.

    PubMed

    Hersh, W R; Hickam, D H

    1992-05-01

    Conventional approaches to indexing medical literature include the human assignment of terms from a controlled vocabulary, such as MeSH, or the computer assignment of all words in the title and abstract as indexing terms. Human indexing suffers from inconsistency, while word-based indexing suffers from the multiple meanings of words. SAPHIRE is a computer program designed to provide indexing using controlled terms that are assigned by computer, based on their occurrence in the title and abstract. In this first evaluation of SAPHIRE, the authors compared the retrieval performance of the three indexing approaches--human-based MEDLINE with text words; machine-based SAPHIRE with text words; and text words only--for searches by measuring recall and precision for each search using a test collection of 200 abstracts. The abstracts were judged by human reviewers for relevance as applied to 12 literature queries. The results suggest that text word indexing is more effective than indexing with MeSH terms. SAPHIRE's indexing performance was slightly inferior but the program has other advantageous features.

  20. Retrieval Practice Can Insulate Items against Intralist Interference: Evidence from the List-Length Effect, Output Interference, and Retrieval-Induced Forgetting

    ERIC Educational Resources Information Center

    Kliegl, Oliver; Bäuml, Karl-Heinz T.

    2016-01-01

    This study sought to determine whether nonselective retrieval practice after study can reduce memories' susceptibility to intralist interference, as it is observed in the list-length effect, output interference, and retrieval-induced forgetting. Across 3 experiments, we compared the effects of nonselective retrieval practice and restudy on…

  1. MWR Retrievals Performance Improvement after Smear Effect Correction

    NASA Astrophysics Data System (ADS)

    Labanda, M. F.; Jacob, M. M.; Farrar, S.; Raimondo, H.; Jones, L.

    2012-12-01

    The SAC-D/Aquarius mission is a cooperative mission developed between CoNAE (Argentine Space Agency) and NASA, that focuses on understanding the interaction between the global water cycle, ocean circulation and climate by measuring sea surface salinity (SSS). One of the main Argentinean instruments is the Microwave Radiometer (MWR), that measures the surface brightness temperature (TB) in a frequency range sensitive to geophysical parameters over the ocean (such as, surface wind speed, rain rate, water vapor, cloud liquid water, and sea ice concentration). MWR is a push-broom 3 channel, Dicke radiometer, operating at K (23.8 GHz H-Pol) and Ka (36.5 GHz, H- & V-Pol) band. The instrument has 16 beams, 8 forward-looking (36.5 GHz) and 8 aft-looking (23.8 GHz). The beams are arranged in a configuration with two incidence angles, one of 52° ( 4 odd beams) and one of 58° (4 even beams), for both forward and aft-looks. Since the first global Tb images, there has been an observed recurring anomalous effect, coined as "Smear Effect". This effect is present in all push-broom beams and results in a "smearing" of Tb observations, that is more noticeable near high contrast areas, such as land/water crossings, rain events, and in the presence of clouds. Geophysical retrieval algorithms based on radiances measured by space borne instruments play a large role in helping scientists monitor the state of the planet. In this sense accurate models are needed. After a detail analysis it was determined that the smear effect strongly affects the geophysical retrieval products. CONAE studied the effect, in a variety of cases, and developed a method to try to mitigate this smearing effect. The correction was applied to Tb counts and with this data the retrievals was reprocessed. We present in this paper a comparison between the results obtained before and after the correction with noticeable improvement in MWR products, i. e., more realistic geophysical retrieval products. The improvement

  2. Semantic analysis of WebGIS Chinese query sentences

    NASA Astrophysics Data System (ADS)

    Xu, Aiping; Bian, Fuling

    2006-10-01

    No matter how much complicated Chinese query sentences may be, they are always made up of query targets, query conditions and grouping segments. The query targets are often at the tail of a sentence or behind the interrogative word. As a result, to comprehend a query sentence, the first step is to get the query targets, and then extraction the query conditions and grouping segments from the rest information of the sentence. The Semantic-analyzing of the query target, query condition and grouping are researched and some corresponding algorithms are presented in this paper. Some groups of Chinese query sentences of different structure be tested, which show that these algorithms are feasible and effective. They are worth further researched.

  3. Theta oscillations predict the detrimental effects of memory retrieval.

    PubMed

    Hanslmayr, Simon; Staudigl, Tobias; Aslan, Alp; Bäuml, Karl-Heinz

    2010-09-01

    Retrieving a target item from episodic memory typically enhances later memory for the retrieved item but causes forgetting of competing irrelevant memories. This finding is termed retrieval-induced forgetting (RIF) and is assumed to be the consequence of an inhibitory mechanism resolving retrieval competition. In the present study, we examined brain oscillatory processes related to RIF, as induced by competitive memory retrieval. Contrasting a competitive with a noncompetitive retrieval condition, we found a stronger increase in early evoked theta (4-7 Hz) activity, which specifically predicted RIF, but not retrieval-induced enhancement. Within the cognitive framework of RIF, these findings suggest that theta oscillations reflect arising interference and its resolution during competitive retrieval in episodic memory. Supplemental materials for this article may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.

  4. A Comparative Analysis of Retrieval Effectiveness for Three Methods of Indexing AIDS-Related Abstracts.

    ERIC Educational Resources Information Center

    Hersh, William R.; Hickam, David H.

    1991-01-01

    Describes SAPHIRE, an experimental information retrieval system featuring concept-based automated indexing, natural language input, and relevance-based retrieval; and compares its retrieval effectiveness with other indexing approaches in a Boolean-based searching environment. Indexing in MEDLINE is described, and a test collection of AIDS…

  5. MPEG-7 multimedia-based query format

    NASA Astrophysics Data System (ADS)

    Chang, Wo

    2006-08-01

    Searching multimedia content for image, audio, and video is getting more attention especially for personal media content due to the affordability of consumer electronic devices such as MP3 recordable players, digital cameras, DV camcorders, and well-integrated smart phones. The precise search and retrieval of the content derived from these devices can be a very challenging task. Many leading edge search engine vendors have been applying sophisticated and advanced indexing and retrieval techniques on various text-based document formats, but when it comes to retrieving multimedia content, searching based on the media clip filename is the most common practice. As a result, there is an imprecise and ineffective user experience for searching multimedia content. This paper presents a new development underway from a joint effort between International Organization for Standardization (ISO)/International Electrotechnial Commission (IEC) Subcommittee (SC) 29 Working Group (WG) 11 MPEG (Moving Picture Experts Group) and WG1 JPEG (Joint Picture Experts Group) for a universal standard query format called MPEG-7 Query Format (MP7QF) as a means to enable a good user experience for consumers searching multimedia content. It also provides the industry with a unified way to accept and respond to user queries. This paper presents the core requirements for such a universal query format.

  6. Exploiting salient semantic analysis for information retrieval

    NASA Astrophysics Data System (ADS)

    Luo, Jing; Meng, Bo; Quan, Changqin; Tu, Xinhui

    2016-11-01

    Recently, many Wikipedia-based methods have been proposed to improve the performance of different natural language processing (NLP) tasks, such as semantic relatedness computation, text classification and information retrieval. Among these methods, salient semantic analysis (SSA) has been proven to be an effective way to generate conceptual representation for words or documents. However, its feasibility and effectiveness in information retrieval is mostly unknown. In this paper, we study how to efficiently use SSA to improve the information retrieval performance, and propose a SSA-based retrieval method under the language model framework. First, SSA model is adopted to build conceptual representations for documents and queries. Then, these conceptual representations and the bag-of-words (BOW) representations can be used in combination to estimate the language models of queries and documents. The proposed method is evaluated on several standard text retrieval conference (TREC) collections. Experiment results on standard TREC collections show the proposed models consistently outperform the existing Wikipedia-based retrieval methods.

  7. Scale-Independent Relational Query Processing

    DTIC Science & Technology

    2013-10-04

    hopes that the bounded plan will exhibit more predictable behaviour as the amount of data in the system grows. In order to quantify the e↵ect of...instead of each node of the tree having only two children , each B-tree node has many. This allows for much larger nodes, each of which can be retrieved by...database grows. Since the actual execution strategy is divorced from the query specified by the developer, it is possible for a new physical query plan to be

  8. Interpreting natural language queries using the UMLS.

    PubMed

    Johnson, S B; Aguirre, A; Peng, P; Cimino, J

    1993-01-01

    This paper describes AQUA (A QUery Analyzer), the natural language front end of a prototype information retrieval system. AQUA translates a user's natural language query into a representation in the Conceptual Graph formalism. The graph is then used by subsequent components to search various resources such as databases of the medical literature. The focus of the parsing method is on semantics rather than syntax, with semantic restrictions being provided by the UMLS Semantic Net. The intent of the approach is to provide a method that can be emulated easily in applications that require simple natural language interfaces.

  9. Query log analysis of an electronic health record search engine.

    PubMed

    Yang, Lei; Mei, Qiaozhu; Zheng, Kai; Hanauer, David A

    2011-01-01

    We analyzed a longitudinal collection of query logs of a full-text search engine designed to facilitate information retrieval in electronic health records (EHR). The collection, 202,905 queries and 35,928 user sessions recorded over a course of 4 years, represents the information-seeking behavior of 533 medical professionals, including frontline practitioners, coding personnel, patient safety officers, and biomedical researchers for patient data stored in EHR systems. In this paper, we present descriptive statistics of the queries, a categorization of information needs manifested through the queries, as well as temporal patterns of the users' information-seeking behavior. The results suggest that information needs in medical domain are substantially more sophisticated than those that general-purpose web search engines need to accommodate. Therefore, we envision there exists a significant challenge, along with significant opportunities, to provide intelligent query recommendations to facilitate information retrieval in EHR.

  10. Query Log Analysis of an Electronic Health Record Search Engine

    PubMed Central

    Yang, Lei; Mei, Qiaozhu; Zheng, Kai; Hanauer, David A.

    2011-01-01

    We analyzed a longitudinal collection of query logs of a full-text search engine designed to facilitate information retrieval in electronic health records (EHR). The collection, 202,905 queries and 35,928 user sessions recorded over a course of 4 years, represents the information-seeking behavior of 533 medical professionals, including frontline practitioners, coding personnel, patient safety officers, and biomedical researchers for patient data stored in EHR systems. In this paper, we present descriptive statistics of the queries, a categorization of information needs manifested through the queries, as well as temporal patterns of the users’ information-seeking behavior. The results suggest that information needs in medical domain are substantially more sophisticated than those that general-purpose web search engines need to accommodate. Therefore, we envision there exists a significant challenge, along with significant opportunities, to provide intelligent query recommendations to facilitate information retrieval in EHR. PMID:22195150

  11. Enhancing Sketch-Based Image Retrieval by Re-Ranking and Relevance Feedback.

    PubMed

    Xueming Qian; Xianglong Tan; Yuting Zhang; Richang Hong; Meng Wang

    2016-01-01

    A sketch-based image retrieval often needs to optimize the tradeoff between efficiency and precision. Index structures are typically applied to large-scale databases to realize efficient retrievals. However, the performance can be affected by quantization errors. Moreover, the ambiguousness of user-provided examples may also degrade the performance, when compared with traditional image retrieval methods. Sketch-based image retrieval systems that preserve the index structure are challenging. In this paper, we propose an effective sketch-based image retrieval approach with re-ranking and relevance feedback schemes. Our approach makes full use of the semantics in query sketches and the top ranked images of the initial results. We also apply relevance feedback to find more relevant images for the input query sketch. The integration of the two schemes results in mutual benefits and improves the performance of the sketch-based image retrieval.

  12. Managing and Querying Whole Slide Images

    PubMed Central

    Wang, Fusheng; Oh, Tae W.; Vergara-Niedermayr, Cristobal; Kurc, Tahsin; Saltz, Joel

    2012-01-01

    High-resolution pathology images provide rich information about the morphological and functional characteristics of biological systems, and are transforming the field of pathology into a new era. To facilitate the use of digital pathology imaging for biomedical research and clinical diagnosis, it is essential to manage and query both whole slide images (WSI) and analytical results generated from images, such as annotations made by humans and computed features and classifications made by computer algorithms. There are unique requirements on modeling, managing and querying whole slide images, including compatibility with standards, scalability, support of image queries at multiple granularities, and support of integrated queries between images and derived results from the images. In this paper, we present our work on developing the Pathology Image Database System (PIDB), which is a standard oriented image database to support retrieval of images, tiles, regions and analytical results, image visualization and experiment management through a unified interface and architecture. The system is deployed for managing and querying whole slide images for In Silico brain tumor studies at Emory University. PIDB is generic and open source, and can be easily used to support other biomedical research projects. It has the potential to be integrated into a Picture Archiving and Communications System (PACS) with powerful query capabilities to support pathology imaging. PMID:22844574

  13. Managing and querying whole slide images

    NASA Astrophysics Data System (ADS)

    Wang, Fusheng; Oh, Tae W.; Vergara-Niedermayr, Cristobal; Kurc, Tahsin; Saltz, Joel

    2012-02-01

    High-resolution pathology images provide rich information about the morphological and functional characteristics of biological systems, and are transforming the field of pathology into a new era. To facilitate the use of digital pathology imaging for biomedical research and clinical diagnosis, it is essential to manage and query both whole slide images (WSI) and analytical results generated from images, such as annotations made by humans and computed features and classifications made by computer algorithms. There are unique requirements on modeling, managing and querying whole slide images, including compatibility with standards, scalability, support of image queries at multiple granularities, and support of integrated queries between images and derived results from the images. In this paper, we present our work on developing the Pathology Image Database System (PIDB), which is a standard oriented image database to support retrieval of images, tiles, regions and analytical results, image visualization and experiment management through a unified interface and architecture. The system is deployed for managing and querying whole slide images for In Silico brain tumor studies at Emory University. PIDB is generic and open source, and can be easily used to support other biomedical research projects. It has the potential to be integrated into a Picture Archiving and Communications System (PACS) with powerful query capabilities to support pathology imaging.

  14. Using relevant regions in image search and query refinement for medical CBIR

    NASA Astrophysics Data System (ADS)

    Kim, Edward; Antani, Sameer; Huang, Xiaolei; Long, L. Rodney; Demner-Fushman, Dina

    2011-03-01

    In clinical decision processes, relevant scientific publications and their associated medical images can provide valuable and insightful information. However, effectively searching through both text and image data is a difficult and arduous task. More specifically in the area of image search, finding similar images (or regions within images) poses another significant hurdle for effective knowledge dissemination. Thus, we propose a method using local regions within images to perform and refine medical image retrieval. In our first example, we define and extract large, characteristic regions within an image, and then show how to use these regions to match a query image to similar content. In our second example, we enable the formulation of a mixed query based upon text, image, and region information, to better represent the end user's search intentions. Given our new framework for region-based queries, we present an improved set of similar search results.

  15. Secure Skyline Queries on Cloud Platform.

    PubMed

    Liu, Jinfei; Yang, Juncheng; Xiong, Li; Pei, Jian

    2017-04-01

    Outsourcing data and computation to cloud server provides a cost-effective way to support large scale data storage and query processing. However, due to security and privacy concerns, sensitive data (e.g., medical records) need to be protected from the cloud server and other unauthorized users. One approach is to outsource encrypted data to the cloud server and have the cloud server perform query processing on the encrypted data only. It remains a challenging task to support various queries over encrypted data in a secure and efficient way such that the cloud server does not gain any knowledge about the data, query, and query result. In this paper, we study the problem of secure skyline queries over encrypted data. The skyline query is particularly important for multi-criteria decision making but also presents significant challenges due to its complex computations. We propose a fully secure skyline query protocol on data encrypted using semantically-secure encryption. As a key subroutine, we present a new secure dominance protocol, which can be also used as a building block for other queries. Finally, we provide both serial and parallelized implementations and empirically study the protocols in terms of efficiency and scalability under different parameter settings, verifying the feasibility of our proposed solutions.

  16. Secure Skyline Queries on Cloud Platform

    PubMed Central

    Liu, Jinfei; Yang, Juncheng; Xiong, Li; Pei, Jian

    2017-01-01

    Outsourcing data and computation to cloud server provides a cost-effective way to support large scale data storage and query processing. However, due to security and privacy concerns, sensitive data (e.g., medical records) need to be protected from the cloud server and other unauthorized users. One approach is to outsource encrypted data to the cloud server and have the cloud server perform query processing on the encrypted data only. It remains a challenging task to support various queries over encrypted data in a secure and efficient way such that the cloud server does not gain any knowledge about the data, query, and query result. In this paper, we study the problem of secure skyline queries over encrypted data. The skyline query is particularly important for multi-criteria decision making but also presents significant challenges due to its complex computations. We propose a fully secure skyline query protocol on data encrypted using semantically-secure encryption. As a key subroutine, we present a new secure dominance protocol, which can be also used as a building block for other queries. Finally, we provide both serial and parallelized implementations and empirically study the protocols in terms of efficiency and scalability under different parameter settings, verifying the feasibility of our proposed solutions.

  17. Large scale study of multiple-molecule queries.

    PubMed

    Nasr, Ramzi J; Swamidass, S Joshua; Baldi, Pierre F

    2009-06-04

    In ligand-based screening, as well as in other chemoinformatics applications, one seeks to effectively search large repositories of molecules in order to retrieve molecules that are similar typically to a single molecule lead. However, in some case, multiple molecules from the same family are available to seed the query and search for other members of the same family.Multiple-molecule query methods have been less studied than single-molecule query methods. Furthermore, the previous studies have relied on proprietary data and sometimes have not used proper cross-validation methods to assess the results. In contrast, here we develop and compare multiple-molecule query methods using several large publicly available data sets and background. We also create a framework based on a strict cross-validation protocol to allow unbiased benchmarking for direct comparison in future studies across several performance metrics. Fourteen different multiple-molecule query methods were defined and benchmarked using: (1) 41 publicly available data sets of related molecules with similar biological activity; and (2) publicly available background data sets consisting of up to 175,000 molecules randomly extracted from the ChemDB database and other sources. Eight of the fourteen methods were parameter free, and six of them fit one or two free parameters to the data using a careful cross-validation protocol. All the methods were assessed and compared for their ability to retrieve members of the same family against the background data set by using several performance metrics including the Area Under the Accumulation Curve (AUAC), Area Under the Curve (AUC), F1-measure, and BEDROC metrics.Consistent with the previous literature, the best parameter-free methods are the MAX-SIM and MIN-RANK methods, which score a molecule to a family by the maximum similarity, or minimum ranking, obtained across the family. One new parameterized method introduced in this study and two previously defined methods

  18. Large scale study of multiple-molecule queries

    PubMed Central

    2009-01-01

    Background In ligand-based screening, as well as in other chemoinformatics applications, one seeks to effectively search large repositories of molecules in order to retrieve molecules that are similar typically to a single molecule lead. However, in some case, multiple molecules from the same family are available to seed the query and search for other members of the same family. Multiple-molecule query methods have been less studied than single-molecule query methods. Furthermore, the previous studies have relied on proprietary data and sometimes have not used proper cross-validation methods to assess the results. In contrast, here we develop and compare multiple-molecule query methods using several large publicly available data sets and background. We also create a framework based on a strict cross-validation protocol to allow unbiased benchmarking for direct comparison in future studies across several performance metrics. Results Fourteen different multiple-molecule query methods were defined and benchmarked using: (1) 41 publicly available data sets of related molecules with similar biological activity; and (2) publicly available background data sets consisting of up to 175,000 molecules randomly extracted from the ChemDB database and other sources. Eight of the fourteen methods were parameter free, and six of them fit one or two free parameters to the data using a careful cross-validation protocol. All the methods were assessed and compared for their ability to retrieve members of the same family against the background data set by using several performance metrics including the Area Under the Accumulation Curve (AUAC), Area Under the Curve (AUC), F1-measure, and BEDROC metrics. Consistent with the previous literature, the best parameter-free methods are the MAX-SIM and MIN-RANK methods, which score a molecule to a family by the maximum similarity, or minimum ranking, obtained across the family. One new parameterized method introduced in this study and two

  19. Effect of component design in retrieved bipolar hip hemiarthroplasty systems.

    PubMed

    Hess, Matthew D; Baker, Erin A; Salisbury, Meagan R; Kaplan, Lige M; Greene, Ryan T; Greene, Perry W

    2013-09-01

    Primary articulation of bipolar hemiarthroplasty systems is at the femoral head-liner interface. The purpose of this study was to compare observed damage modes on 36 retrieved bipolar systems with implant, demographic, intraoperative, and radiographic data to elucidate the effects of component design, specifically locking mechanism, on clinical performance. Retrieved bipolar hip hemiarthroplasty systems of 3 different design types were obtained, disassembled, and evaluated macro- and microscopically for varying modes of wear, including abrasion, burnishing, embedding, scratching, and pitting. Clinical record review and radiographic analysis were performed by a senior orthopedic surgery resident. Average bipolar hip hemiarthroplasty system term of service was 46 months (range, 0.27-187 months). All devices contained wear debris captured within the articulating space between the femoral head and liner. In 31% of patients without infection, lucency was observed on immediate prerevision radiographs. The system with a leaf locking mechanism showed significantly increased radiographically observed osteolysis (P=.03) compared with a system with a stopper ring locking mechanism. In addition, implant design and observed damage modes, including pitting and third-body particle embedding, were significantly associated with radiographically observed osteolysis.

  20. Phase function effects for ocean color retrieval algorithm

    NASA Astrophysics Data System (ADS)

    Du, KePing; Lee, Zhongping

    2010-10-01

    Inherent optical properties (IOPs), e.g., absorption, back scattering coefficients, and volume scattering function, are important parameters for radiance transfer simulation. Commercially available instruments (e.g., Wetlabs ACS, BB9, etc, and HOBILabs a-sphere, HS6, etc) basically only measure absorption and back scattering coefficients. In this paper, we used the same IOPs of International Ocean-Colour Coordinating Group (IOCCG) report 5 and Hydrolight to simulate the radiance distribution, however, different phase functions, say, a new phase function derived from the measured data by multispectral volume scattering meter (MVSM) in coastal waters, the widely used Petzold average phase function, and the Fournier-Forand (FF) phase function, were employed in the simulations. The simulation results were used to develop the retrieval algorithm with angular effects correction based on the quasi-analytical algorithm(QAA) developed by Lee et al.. Results showed that not only the back scattering probability, but also the angular shape of phase function are important for ocean color retrieval algorithm. Considering the importance of phase function in ocean color remote sensing, methods to validate the phase function data should be developed.

  1. The properties of retrieval cues constrain the picture superiority effect.

    PubMed

    Weldon, M S; Roediger, H L; Challis, B H

    1989-01-01

    In three experiments, we examined why pictures are remembered better than words on explicit memory tests like recall and recognition, whereas words produce more priming than pictures on some implicit tests, such as word-fragment and word-stem completion (e.g., completing -l-ph-nt or ele----- as elephant). One possibility is that pictures are always more accessible than words if subjects are given explicit retrieval instructions. An alternative possibility is that the properties of the retrieval cues themselves constrain the retrieval processes engaged; word fragments might induce data-driven (perceptually based) retrieval, which favors words regardless of the retrieval instructions. Experiment 1 demonstrated that words were remembered better than pictures on both the word-fragment and word-stem completion tasks under both implicit and explicit retrieval conditions. In Experiment 2, pictures were recalled better than words with semantically related extralist cues. In Experiment 3, when semantic cues were combined with word fragments, pictures and words were recalled equally well under explicit retrieval conditions, but words were superior to pictures under implicit instructions. Thus, the inherently data-limited properties of fragmented words limit their use in accessing conceptual codes. Overall, the results indicate that retrieval operations are largely determined by properties of the retrieval cues under both implicit and explicit retrieval conditions.

  2. Robust segmentation and retrieval of environmental sounds

    NASA Astrophysics Data System (ADS)

    Wichern, Gordon

    The proliferation of mobile computing has provided much of the world with the ability to record any sound of interest, or possibly every sound heard in a lifetime. The technology to continuously record the auditory world has applications in surveillance, biological monitoring of non-human animal sounds, and urban planning. Unfortunately, the ability to record anything has led to an audio data deluge, where there are more recordings than time to listen. Thus, access to these archives depends on efficient techniques for segmentation (determining where sound events begin and end), indexing (storing sufficient information with each event to distinguish it from other events), and retrieval (searching for and finding desired events). While many such techniques have been developed for speech and music sounds, the environmental and natural sounds that compose the majority of our aural world are often overlooked. The process of analyzing audio signals typically begins with the process of acoustic feature extraction where a frame of raw audio (e.g., 50 milliseconds) is converted into a feature vector summarizing the audio content. In this dissertation, a dynamic Bayesian network (DBN) is used to monitor changes in acoustic features in order to determine the segmentation of continuously recorded audio signals. Experiments demonstrate effective segmentation performance on test sets of environmental sounds recorded in both indoor and outdoor environments. Once segmented, every sound event is indexed with a probabilistic model, summarizing the evolution of acoustic features over the course of the event. Indexed sound events are then retrieved from the database using different query modalities. Two important query types are sound queries (query-by-example) and semantic queries (query-by-text). By treating each sound event and semantic concept in the database as a node in an undirected graph, a hybrid (content/semantic) network structure is developed. This hybrid network can

  3. The Challenge of Commercial Document Retrieval, Part II: A Strategy for Document Searching Based on Identifiable Document Partitions.

    ERIC Educational Resources Information Center

    Blair, David C.

    2002-01-01

    Discussion of commercial document retrieval focuses on a two-part searching procedure based on identifiable partitions. Topics include system growth and the effects of information technology; content searching on large databases, including partitioning; the granularity of context; resolving queries; document retrieval and the World Wide Web; and…

  4. The humour effect: differential processing and privileged retrieval.

    PubMed

    Schmidt, Stephen R

    2002-03-01

    The effects of humour on memory and heart rate were explored as a function of experimental design. In within-subject manipulations, original humorous cartoons were better remembered than the literal translations and weird cartoons, whereas literal and weird cartoons were equally well remembered. Good recall of humorous cartoons occurred at the expense of recall of non-humorous cartoons. Secondary heart-rate deceleration was larger in response to original cartoons than to literal and weird cartoons. Neither the memory nor the heart-rate effects were found in between-subjects comparisons. The results were consistent with differential processing resulting from within-list contrasts. However, retrieval processes also favoured good recall of humorous material.

  5. A Problem in Information Retrieval with Fuzzy Sets.

    ERIC Educational Resources Information Center

    Buell, Duncan A.

    1985-01-01

    Discussion of problems with fuzzy subsets in document retrieval highlights attempts to invent a system of weighted fuzzy queries in which weights correspond to relative importance of each term in query as whole, and use of Kantor's Logic for Retrieval as an alternative to Boolean queries. Six references are cited. (EJS)

  6. A Problem in Information Retrieval with Fuzzy Sets.

    ERIC Educational Resources Information Center

    Buell, Duncan A.

    1985-01-01

    Discussion of problems with fuzzy subsets in document retrieval highlights attempts to invent a system of weighted fuzzy queries in which weights correspond to relative importance of each term in query as whole, and use of Kantor's Logic for Retrieval as an alternative to Boolean queries. Six references are cited. (EJS)

  7. Declarative Visualization Queries

    NASA Astrophysics Data System (ADS)

    Pinheiro da Silva, P.; Del Rio, N.; Leptoukh, G. G.

    2011-12-01

    In an ideal interaction with machines, scientists may prefer to write declarative queries saying "what" they want from a machine than to write code stating "how" the machine is going to address the user request. For example, in relational database, users have long relied on specifying queries using Structured Query Language (SQL), a declarative language to request data results from a database management system. In the context of visualizations, we see that users are still writing code based on complex visualization toolkit APIs. With the goal of improving the scientists' experience of using visualization technology, we have applied this query-answering pattern to a visualization setting, where scientists specify what visualizations they want generated using a declarative SQL-like notation. A knowledge enhanced management system ingests the query and knows the following: (1) know how to translate the query into visualization pipelines; and (2) how to execute the visualization pipelines to generate the requested visualization. We define visualization queries as declarative requests for visualizations specified in an SQL like language. Visualization queries specify what category of visualization to generate (e.g., volumes, contours, surfaces) as well as associated display attributes (e.g., color and opacity), without any regards for implementation, thus allowing scientists to remain partially unaware of a wide range of visualization toolkit (e.g., Generic Mapping Tools and Visualization Toolkit) specific implementation details. Implementation details are only a concern for our knowledge-based visualization management system, which uses both the information specified in the query and knowledge about visualization toolkit functions to construct visualization pipelines. Knowledge about the use of visualization toolkits includes what data formats the toolkit operates on, what formats they output, and what views they can generate. Visualization knowledge, which is not

  8. Improving Web Search for Difficult Queries

    ERIC Educational Resources Information Center

    Wang, Xuanhui

    2009-01-01

    Search engines have now become essential tools in all aspects of our life. Although a variety of information needs can be served very successfully, there are still a lot of queries that search engines can not answer very effectively and these queries always make users feel frustrated. Since it is quite often that users encounter such "difficult…

  9. Improving Web Search for Difficult Queries

    ERIC Educational Resources Information Center

    Wang, Xuanhui

    2009-01-01

    Search engines have now become essential tools in all aspects of our life. Although a variety of information needs can be served very successfully, there are still a lot of queries that search engines can not answer very effectively and these queries always make users feel frustrated. Since it is quite often that users encounter such "difficult…

  10. Image indexing and retrieval using linear phase coefficient composite filters

    NASA Astrophysics Data System (ADS)

    Carlotto, Mark J.

    1996-01-01

    Content-based retrieval techniques can be characterized in several ways: by the manner in which image data are indexed, by the level of specificity/generality of the query and response of the system, by the type of query (e.g., iconic or symbolic), and by the kind of information used (intrinsic image features or attached information such as text). The method described in this paper automatically indexes images in the database, and is intended to retrieve specific objects by image query based on inherent image content. Our method is actually quite similar to object recognition except that instead of searching a single image for a given object, an entire database of images is examined. The approach uses linear phase coefficient composite (LPCC) filters to encode and match queries consisting of multiple images (e.g., representative views of an object of interest) against multiple images in the database simultaneously. Retrieval is a two-step process that first isolates those portions of the database containing images that match the query, and then identifies the specific images. Our use of LPCC filters exploits phase information to retrieve specific images that match the query from the database. The results from the experiments suggest that phase information can be used to index and retrieve multiple images from a database in parallel, and that large numbers of operations can be performed simultaneously using a complex number representation. In one experiment well over 100 real correlations were effectively performed by a single complex correlation. Problems encountered in processing video data are discussed.

  11. Differentiation of subsequent memory effects between retrieval practice and elaborative study.

    PubMed

    Liu, Yi; Rosburg, Timm; Gao, Chuanji; Weber, Christine; Guo, Chunyan

    2017-07-01

    Retrieval practice enhances memory retention more than re-studying. The underlying mechanisms of this retrieval practice effect have remained widely unclear. According to the elaborative retrieval hypothesis, activation of elaborative information occurs to a larger extent during testing than re-studying. In contrast, the episodic context account has suggested that recollecting prior episodic information (especially the temporal context) contributes to memory retention. To adjudicate the distinction between these two accounts, the present study used the classical retrieval practice effect paradigm to compare retrieval practice and elaborative study. In an initial behavioral experiment, retrieval practice produced greater retention than elaboration and re-studying in a one-week delayed test. In a subsequent event-related potential (ERP) experiment, retrieval practice resulted in reliably superior accuracy in the delayed test compared to elaborative study. In the ERPs, a frontally distributed subsequent memory effect (SME), starting at 300ms, occurred in the elaborative study condition, but not in the retrieval practice condition. A parietal SME emerged in the retrieval practice condition from 500 to 700ms, but was absent in the elaborative study condition. After 700ms, a late SME was present in the retrieval practice condition, but not in the elaborative study condition. Moreover, SMEs lasted longer in retrieval practice than in elaboration. The frontal SME in the elaborative study condition might be related to semantic processing or working memory-based elaboration, whereas the parietal and widespread SME in the retrieval practice condition might be associated with episodic recollection processes. These findings contradict the elaborative retrieval theory, and suggest that contextual recollection rather than activation of semantic information contributes to the retrieval practice effect, supporting the episodic context account. Copyright © 2017. Published by

  12. Relational Thesauri in Information Retrieval.

    ERIC Educational Resources Information Center

    Wang, Yih-Chen; Vandendorpe, James

    1985-01-01

    Describes design and development of a thesaurus based on lexical-semantic relations, and compares results of experiments with queries enhanced using thesauri based on several different groups of relations against performance with original queries run on IRS information retrieval system developed at Illinois Institute of Technology. Twenty-one…

  13. Cross-Language Information Retrieval.

    ERIC Educational Resources Information Center

    Oard, Douglas W.; Diekema, Anne R.

    1998-01-01

    Reviews research and practice in cross-language information retrieval (CLIR) that seeks to support the process of finding documents written in one natural language with automated systems that can accept queries expressed in other languages. Addresses user needs, document preprocessing, query formulation, matching strategies, sources of translation…

  14. Retrieval of effective cloud field parameters from radiometric data

    NASA Astrophysics Data System (ADS)

    Paulescu, Marius; Badescu, Viorel; Brabec, Marek

    2017-06-01

    Clouds play a key role in establishing the Earth's climate. Real cloud fields are very different and very complex in both morphological and microphysical senses. Consequently, the numerical description of the cloud field is a critical task for accurate climate modeling. This study explores the feasibility of retrieving the effective cloud field parameters (namely the cloud aspect ratio and cloud factor) from systematic radiometric measurements at high frequency (measurement is taken every 15 s). Two different procedures are proposed, evaluated, and discussed with respect to both physical and numerical restrictions. None of the procedures is classified as best; therefore, the specific advantages and weaknesses are discussed. It is shown that the relationship between the cloud shade and point cloudiness computed using the estimated cloud field parameters recovers the typical relationship derived from measurements.

  15. Benchmarking Query Execution Robustness

    NASA Astrophysics Data System (ADS)

    Wiener, Janet L.; Kuno, Harumi; Graefe, Goetz

    Benchmarks that focus on running queries on a well-tuned database system ignore a long-standing problem: adverse runtime conditions can cause database system performance to vary widely and unexpectedly. When the query execution engine does not exhibit resilience to these adverse conditions, addressing the resultant performance problems can contribute significantly to the total cost of ownership for a database system in over-provisioning, lost efficiency, and increased human administrative costs. For example, focused human effort may be needed to manually invoke workload management actions or fine-tune the optimization of specific queries.

  16. Advanced Feedback Methods in Information Retrieval.

    ERIC Educational Resources Information Center

    Salton, G.; And Others

    1985-01-01

    In this study, automatic feedback techniques are applied to Boolean query statements in online information retrieval to generate improved query statements based on information contained in previously retrieved documents. Feedback operations are carried out using conventional Boolean logic and extended logic. Experimental output is included to…

  17. Improved data retrieval from TreeBASE via taxonomic and linguistic data enrichment

    PubMed Central

    Anwar, Nadia; Hunt, Ela

    2009-01-01

    Background TreeBASE, the only data repository for phylogenetic studies, is not being used effectively since it does not meet the taxonomic data retrieval requirements of the systematics community. We show, through an examination of the queries performed on TreeBASE, that data retrieval using taxon names is unsatisfactory. Results We report on a new wrapper supporting taxon queries on TreeBASE by utilising a Taxonomy and Classification Database (TCl-Db) we created. TCl-Db holds merged and consolidated taxonomic names from multiple data sources and can be used to translate hierarchical, vernacular and synonym queries into specific query terms in TreeBASE. The query expansion supported by TCl-Db shows very significant information retrieval quality improvement. The wrapper can be accessed at the URL The methodology we developed is scalable and can be applied to new data, as those become available in the future. Conclusion Significantly improved data retrieval quality is shown for all queries, and additional flexibility is achieved via user-driven taxonomy selection. PMID:19426482

  18. Indexing and retrieval strategies for natural language fact retrieval

    SciTech Connect

    Kolodner, J.L.

    1983-09-01

    Researchers in artificial intelligence have recently become interested in natural language fact retrieval; currently, their research is at a point where it can begin contributing to the field of information retrieval. In this paper, strategies for a natural language fact retrieval system are mapped out, and approaches to many of the organization and retrieval problems are presented. The CYRUS system, which keeps track of important people and is queried in English, is presented and used to illustrate those solutions. 30 references.

  19. The Effect of User Characteristics on the Efficiency of Visual Querying

    ERIC Educational Resources Information Center

    Bak, Peter; Meyer, Joachim

    2011-01-01

    Information systems increasingly provide options for visually inspecting data during the process of information discovery and exploration. Little research has dealt so far with user interactions with these systems, and specifically with the effects of characteristics of the displayed data and the user on performance with such systems. The study…

  20. The Effect of User Characteristics on the Efficiency of Visual Querying

    ERIC Educational Resources Information Center

    Bak, Peter; Meyer, Joachim

    2011-01-01

    Information systems increasingly provide options for visually inspecting data during the process of information discovery and exploration. Little research has dealt so far with user interactions with these systems, and specifically with the effects of characteristics of the displayed data and the user on performance with such systems. The study…

  1. Interfering Effects of Retrieval in Learning New Information

    ERIC Educational Resources Information Center

    Finn, Bridgid; Roediger, Henry L., III

    2013-01-01

    In 7 experiments, we explored the role of retrieval in associative updating, that is, in incorporating new information into an associative memory. We tested the hypothesis that retrieval would facilitate incorporating a new contextual detail into a learned association. Participants learned 3 pieces of information--a person's face, name, and…

  2. The effect of cue content on retrieval from autobiographical memory.

    PubMed

    Uzer, Tugba; Brown, Norman R

    2017-01-01

    It has long been argued that personal memories are usually generated in an effortful search process in word-cueing studies. However, recent research (Uzer, Lee, & Brown, 2012) shows that direct retrieval of autobiographical memories, in response to word cues, is common. This invites the question of whether direct retrieval phenomenon is generalizable beyond the standard laboratory paradigm. Here we investigated prevalence of direct retrieval of autobiographical memories cued by specific and individuated cues versus generic cues. In Experiment 1, participants retrieved memories in response to cues from their own life (e.g., the names of friends) and generic words (e.g., chair). In Experiment 2, participants provided their personal cues two or three months prior to coming to the lab (min: 75days; max: 100days). In each experiment, RT was measured and participants reported whether memories were directly retrieved or generated on each trial. Results showed that personal cues elicited a high rate of direct retrieval. Personal cues were more likely to elicit direct retrieval than generic word cues, and as a consequence, participants responded faster, on average, to the former than to the latter. These results challenge the constructive view of autobiographical memory and suggest that autobiographical memories consist of pre-stored event representations, which are largely governed by associative mechanisms. These demonstrations offer theoretically interesting questions such as why are we not overwhelmed with directly retrieved memories cued by everyday familiar surroundings?

  3. Interfering Effects of Retrieval in Learning New Information

    ERIC Educational Resources Information Center

    Finn, Bridgid; Roediger, Henry L., III

    2013-01-01

    In 7 experiments, we explored the role of retrieval in associative updating, that is, in incorporating new information into an associative memory. We tested the hypothesis that retrieval would facilitate incorporating a new contextual detail into a learned association. Participants learned 3 pieces of information--a person's face, name, and…

  4. SAM Methods Query

    EPA Pesticide Factsheets

    Laboratories measuring target chemical, radiochemical, pathogens, and biotoxin analytes in environmental samples can use this online query tool to identify analytical methods included in EPA's Selected Analytical Methods for Environmental Remediation

  5. SAM Chemical Methods Query

    EPA Pesticide Factsheets

    Laboratories measuring target chemical, radiochemical, pathogens, and biotoxin analytes in environmental samples can use this online query tool to identify analytical methods in EPA's Selected Analytical Methods for Environmental Remediation and Recovery

  6. SAM Pathogen Methods Query

    EPA Pesticide Factsheets

    Laboratories measuring target pathogen analytes in environmental samples can use this online query tool to identify analytical methods in EPA's Selected Analytical Methods for Environmental Remediation and Recovery for select pathogens.

  7. SAM Biotoxin Methods Query

    EPA Pesticide Factsheets

    Laboratories measuring target biotoxin analytes in environmental samples can use this online query tool to identify analytical methods included in EPA's Selected Analytical Methods for Environmental Remediation and Recovery for select biotoxins.

  8. SAM Radiochemical Methods Query

    EPA Pesticide Factsheets

    Laboratories measuring target radiochemical analytes in environmental samples can use this online query tool to identify analytical methods in EPA's Selected Analytical Methods for Environmental Remediation and Recovery for select radiochemical analytes.

  9. Retrieval practice can insulate items against intralist interference: Evidence from the list-length effect, output interference, and retrieval-induced forgetting.

    PubMed

    Kliegl, Oliver; Bäuml, Karl-Heinz T

    2016-02-01

    This study sought to determine whether nonselective retrieval practice after study can reduce memories' susceptibility to intralist interference, as it is observed in the list-length effect, output interference, and retrieval-induced forgetting. Across 3 experiments, we compared the effects of nonselective retrieval practice and restudy on previously studied material with regard to these 3 forms of episodic forgetting. When study of an item list was followed by a restudy cycle, recall from a longer list was worse than recall from a shorter list (list-length effect), preceding recall of studied nontarget items impaired recall of the list's target items (output interference), and repeated selective retrieval of some list items attenuated recall of other nonretrieved items at test (retrieval-induced forgetting). In contrast, none of these effects arose when study of the list was followed by a nonselective retrieval cycle. The findings are consistent with a combination of contextual variability theory and a variant of study-phase retrieval theory that assumes that retrieval can create more distinct context features for retrieved items than restudy does for restudied items, thus reducing items' susceptibility to interference relative to restudy cycles. The findings add to the view that nonselective retrieval practice can stabilize and consolidate memories.

  10. Multi-threaded Query Agent and Engine for a Very Large Astronomical Database

    NASA Astrophysics Data System (ADS)

    Thakkar, A. R.; Kunszt, P. Z.; Szalay, A. S.; Szokoly, G. P.

    We describe the Query Agent and Query Engine for the Science Archive of the Sloan Digital Sky Survey. In our client-server model, a GUI client communicates with a Query Agent that retrieves the requested data from the repository (a commercial ODBMS). The multi-threaded Agent is able to maintain multiple concurrent user sessions as well as multiple concurrent queries within each session. We describe the parallel, distributed design of the Query Agent and present the results of performance benchmarks that we have run using typical queries on our test data. We also report on our experiences with loading large amounts of data into Objectivity.

  11. Neural cryptography with queries

    NASA Astrophysics Data System (ADS)

    Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

    2005-01-01

    Neural cryptography is based on synchronization of tree parity machines by mutual learning. We extend previous key-exchange protocols by replacing random inputs with queries depending on the current state of the neural networks. The probability of a successful attack is calculated for different model parameters using numerical simulations. The results show that queries restore the security against cooperating attackers. The success probability can be reduced without increasing the average synchronization time.

  12. IPSec Database Query Acceleration

    NASA Astrophysics Data System (ADS)

    Ferrante, Alberto; Chandra, Satish; Piuri, Vincenzo

    IPSec is a suite of protocols that adds security to communications at the IP level. Protocols within IPSec make extensive use of two databases, namely the Security Policy Database (SPD) and the Security Association Database (SAD). The ability to query the SPD quickly is fundamental as this operation needs to be done for each incoming or outgoing IP packet, even if no IPSec processing needs to be applied on it. This may easily result in millions of query per second in gigabit networks.

  13. Advanced Query Techniques.

    DTIC Science & Technology

    1979-10-01

    structures I* Data structures a. parse tree D. resolved intermediate query c. data access patn d. lists of matcning i-stances e. requestea fielas 2. Taules... tree (or a forest of trees ). A data relation riow Jescriptively corresponds to a downward oath of label words in tre nierarchy. 4e can reinforce this...general Page 3-10 Handling Natural languaqe Queries syntax-driven narsinq alooritnm for context- tree lanquaqes (41, further auqmented to accept syntactic

  14. A query for effective mean particle size in dry and high-moisture corns.

    PubMed

    Hoffman, P C; Mertens, D R; Larson, J; Coblentz, W K; Shaver, R D

    2012-06-01

    The objective of this study was to investigate whether prediction of fermentation potential (FP) of dry and high-moisture (HM) corns could be improved by using a concept of effective (e) mean particle size (MPS). A set of FP standards was created by processing a single lot of Reid Yellow Dent (RYD) corn to achieve MPS of 3,778, 2,786, 2,282, 1,808, 1,410, 806, 586, 378, 308, 226, and 105 μm. In vitro gas production of RYD standards was measured, and peak absolute rate (PAR) of gas production (mL/0.2 g of DM/h) was used to establish a standard relationship between PAR and MPS. To identify factors other than MPS affecting FP, the MPS and nutrient composition of 36 diverse samples of dry (n=18) and HM (n=18) corns were determined. Composition included dry matter (DM), crude protein, soluble crude protein, neutral detergent fiber, starch, NH₃-N, prolamin protein, and fat. In vitro gas production of undried, unground dry and HM corns was measured, and PAR, time of peak absolute rate (h), maximum cumulative gas production (mL/0.2 g of DM), gas production fractional rate (h⁻¹), and lag (h) were determined. Nonlinear relationships between MPS, defined as the dependent variable, and PAR, as an independent variable, were used to identify FP deviations unexplained by MPS. When no variation in nutritional composition was present (RYD standards), the relationship between PAR and MPS was described by an exponential decay model [RYD_MPS=9,006 × e((-0.452 × PAR)); R²=0.96]. For diverse dry and HM corn populations, the variation in MPS explained by PAR was diminished (R²=0.50). To investigate factors that diminish the relationship between MPS and PAR in diverse corns, relative residual (rr) MPS was determined [rrMPS = (MPS - RYD_MPS)/MPS], where RYD_MPS was predicted from the PAR of diverse dry and HM corn. The rrMPS was most highly related to prolamin protein [rrMPS(dry)=0.58-0.15 × (prolamin protein, % of DM); R²=0.43] and NH₃-N [rrMPS(HM)=0.21+0.08 × (NH

  15. The effects of retrieval ease on health issue judgments: implications for campaign strategies.

    PubMed

    Chang, Chingching

    2010-12-01

    This paper examines the effects of retrieving information about a health ailment on judgments of the perceived severity of the disease and self-efficacy regarding prevention and treatment. The literature on metacognition suggests that recall tasks render two types of information accessible: the retrieved content, and the subjective experience of retrieving the content. Both types of information can influence judgments. Content-based thinking models hold that the more instances of an event people can retrieve, the higher they will estimate the frequency of the event to be. In contrast, experience-based thinking models suggest that when people experience difficulty in retrieving information regarding an event, they rate the event as less likely to occur. In the first experiment, ease of retrieval was manipulated by asking participants to list either a high or low number of consequences of an ailment. As expected, retrieval difficulty resulted in lower perceived disease severity. In the second experiment, ease of retrieval was manipulated by varying the number of disease prevention or treatment measures participants attempted to list. As predicted, retrieval difficulty resulted in lower self-efficacy regarding prevention and treatment. In experiment three, when information regarding a health issue was made accessible by exposure to public service announcements (PSAs), ease-of-retrieval effects were attenuated. Finally, in experiment four, exposure to PSAs encouraged content-based judgments when the issue was of great concern.

  16. An SQL query generator for CLIPS

    NASA Technical Reports Server (NTRS)

    Snyder, James; Chirica, Laurian

    1990-01-01

    As expert systems become more widely used, their access to large amounts of external information becomes increasingly important. This information exists in several forms such as statistical, tabular data, knowledge gained by experts and large databases of information maintained by companies. Because many expert systems, including CLIPS, do not provide access to this external information, much of the usefulness of expert systems is left untapped. The scope of this paper is to describe a database extension for the CLIPS expert system shell. The current industry standard database language is SQL. Due to SQL standardization, large amounts of information stored on various computers, potentially at different locations, will be more easily accessible. Expert systems should be able to directly access these existing databases rather than requiring information to be re-entered into the expert system environment. The ORACLE relational database management system (RDBMS) was used to provide a database connection within the CLIPS environment. To facilitate relational database access a query generation system was developed as a CLIPS user function. The queries are entered in a CLlPS-like syntax and are passed to the query generator, which constructs and submits for execution, an SQL query to the ORACLE RDBMS. The query results are asserted as CLIPS facts. The query generator was developed primarily for use within the ICADS project (Intelligent Computer Aided Design System) currently being developed by the CAD Research Unit in the California Polytechnic State University (Cal Poly). In ICADS, there are several parallel or distributed expert systems accessing a common knowledge base of facts. Expert system has a narrow domain of interest and therefore needs only certain portions of the information. The query generator provides a common method of accessing this information and allows the expert system to specify what data is needed without specifying how to retrieve it.

  17. Extended query refinement for content-based access to large medical-image databases

    NASA Astrophysics Data System (ADS)

    Lehmann, Thomas M.; Plodowski, Bartosz; Spitzer, Klaus; Wein, Berthold B.; Ney, Hermann; Seidl, Thomas

    2004-04-01

    The differentiating characteristics of text versus images and their impact on large medical image databases intended to allow content-based indexing and retrieval have recently been explored. For the design of powerful user interfaces, we propose a grouping of the various mechanisms into four classes: (i) output modules, (ii) parameter modules, (iii) transaction modules, and (iv) process modules, all of which being controlled by a detailed query logging. Relevance feedback by the physician loops the input, search, and output sequence and is commonly accepted to be most effective for query refinement. Our modular concept provides two additional loops of interaction. Based on the detailed logging of user interaction, an inner loop allows to step back to any previous answer that was given by the system during the interactive session. Boolean linkage of successive queries is provided by an outer loop. Nonetheless, the entire data flow is still controlled within a single web page by means of simple decision rules that are implemented only using push buttons, which can be handled most easily. Our approach is exemplified by means of an application for content-based access to medical images of similar modality, orientation, and body region using global features that model gray scale, texture, structure and global shape characteristics. The three nested loops for interaction provide a maximum of flexibility within a minimum of complexity. The resulting extended query refinement has a significant impact for content-based retrieval in medical applications (IRMA).

  18. Building and Querying RDF/OWL Database of Semantically Annotated Nuclear Medicine Images.

    PubMed

    Hwang, Kyung Hoon; Lee, Haejun; Koh, Geon; Willrett, Debra; Rubin, Daniel L

    2017-02-01

    As the use of positron emission tomography-computed tomography (PET-CT) has increased rapidly, there is a need to retrieve relevant medical images that can assist image interpretation. However, the images themselves lack the explicit information needed for query. We constructed a semantically structured database of nuclear medicine images using the Annotation and Image Markup (AIM) format and evaluated the ability the AIM annotations to improve image search. We created AIM annotation templates specific to the nuclear medicine domain and used them to annotate 100 nuclear medicine PET-CT studies in AIM format using controlled vocabulary. We evaluated image retrieval from 20 specific clinical queries. As the gold standard, two nuclear medicine physicians manually retrieved the relevant images from the image database using free text search of radiology reports for the same queries. We compared query results with the manually retrieved results obtained by the physicians. The query performance indicated a 98 % recall for simple queries and a 89 % recall for complex queries. In total, the queries provided 95 % (75 of 79 images) recall, 100 % precision, and an F1 score of 0.97 for the 20 clinical queries. Three of the four images missed by the queries required reasoning for successful retrieval. Nuclear medicine images augmented using semantic annotations in AIM enabled high recall and precision for simple queries, helping physicians to retrieve the relevant images. Further study using a larger data set and the implementation of an inference engine may improve query results for more complex queries.

  19. A Generic Metadata Query Tool.

    ERIC Educational Resources Information Center

    Verhoeven, B.; Duval, E.; Olivie, H.

    This paper discusses a generic query tool that enables an end user to query a metadata store through filters that impose search criteria on attributes. The Metadata Query Tool (MQT) is generic in the sense that it dynamically creates its user interface, based on configuration files that define the metadata scheme and the query functionalities.…

  20. Querying Safety Cases

    NASA Technical Reports Server (NTRS)

    Denney, Ewen W.; Naylor, Dwight; Pai, Ganesh

    2014-01-01

    Querying a safety case to show how the various stakeholders' concerns about system safety are addressed has been put forth as one of the benefits of argument-based assurance (in a recent study by the Health Foundation, UK, which reviewed the use of safety cases in safety-critical industries). However, neither the literature nor current practice offer much guidance on querying mechanisms appropriate for, or available within, a safety case paradigm. This paper presents a preliminary approach that uses a formal basis for querying safety cases, specifically Goal Structuring Notation (GSN) argument structures. Our approach semantically enriches GSN arguments with domain-specific metadata that the query language leverages, along with its inherent structure, to produce views. We have implemented the approach in our toolset AdvoCATE, and illustrate it by application to a fragment of the safety argument for an Unmanned Aircraft System (UAS) being developed at NASA Ames. We also discuss the potential practical utility of our query mechanism within the context of the existing framework for UAS safety assurance.

  1. Retrievals and Comparisons of Various MODIS-Spectrum Inferred Water Cloud Droplet Effective Radii

    NASA Technical Reports Server (NTRS)

    Fu-Lung, Chang; Minnis, Patrick; Lin, Bin; Sunny, Sun-Mack; Khaiyer, Mandana M.

    2007-01-01

    Cloud droplet effective radius retrievals from different Aqua MODIS nearinfrared channels (2.1- micrometer, 3.7- micrometer, and 1.6- micrometer) show considerable differences even among most confident QC pixels. Both Collection 004 and Collection 005 MOD06 show smaller mean effective radii at 3.7- micrometer wavelength than at 2.1- micrometer and 1.6- micrometer wavelengths. Differences in effective radius retrievals between Collection 004 and Collection 005 may be affected by cloud top height/temperature differences, which mainly occur for optically thin clouds. Changes in cloud top height and temperature for thin clouds have different impacts on the effective radius retrievals from 2.1- micrometer, 3.7- micrometer, and 1.6- micrometer channels. Independent retrievals (this study) show, on average, more consistency in the three effective radius retrievals. This study is for Aqua MODIS only.

  2. Measured space environmental effects to LDEF during retrieval

    NASA Astrophysics Data System (ADS)

    Maag, Carl R.; Linder, W. Kelly; Borson, Eugene N.

    1993-06-01

    Data gathered by the Interim Operational Contamination Monitor (IOCM) with regard to the effect of the space environment on the STS-32 Shuttle mission and on the Long Duration Exposure Facility (LDEF) are reported. IOCM measures the deposition of molecular and particulate contamination during all flight phases. It also measures the thermophysical properties of thermal control surfaces by calorimetry, the flux of the ambient atomic oxygen environment, the incident solar flux, and the absolute ambient pressure in the payload bay. The IOCM also provides a structure and sample holders for the exposure of passive material samples to the space environment. One of the more salient results from the STS-32 flight suggests that the LDEF emitted a large number of particulates after berthing into the Shuttle. The mission atomic oxygen fluence was also calculated. Although the fluence was low by normal standards, the Kapton (trademark) passive samples exhibited the onset of erosion. Orbital debris and micrometeoroid impacts also occurred during the retrieval mission. The average perforation diameter was approximately 1.25 micrometers. The largest perforation diameter was measured at 65 micrometers.

  3. Measured space environmental effects to LDEF during retrieval

    NASA Technical Reports Server (NTRS)

    Maag, Carl R.; Linder, W. Kelly; Borson, Eugene N.

    1993-01-01

    Data gathered by the Interim Operational Contamination Monitor (IOCM) with regard to the effect of the space environment on the STS-32 Shuttle mission and on the Long Duration Exposure Facility (LDEF) are reported. IOCM measures the deposition of molecular and particulate contamination during all flight phases. It also measures the thermophysical properties of thermal control surfaces by calorimetry, the flux of the ambient atomic oxygen environment, the incident solar flux, and the absolute ambient pressure in the payload bay. The IOCM also provides a structure and sample holders for the exposure of passive material samples to the space environment. One of the more salient results from the STS-32 flight suggests that the LDEF emitted a large number of particulates after berthing into the Shuttle. The mission atomic oxygen fluence was also calculated. Although the fluence was low by normal standards, the Kapton (trademark) passive samples exhibited the onset of erosion. Orbital debris and micrometeoroid impacts also occurred during the retrieval mission. The average perforation diameter was approximately 1.25 micrometers. The largest perforation diameter was measured at 65 micrometers.

  4. The Effect of Bilingual Term List Size on Dictionary-Based Cross-Language Information Retrieval

    DTIC Science & Technology

    2006-01-01

    untranslatable terms that might appear in queries in order to focus our future efforts to improve dictionary cov- erage. When assessing coverage effects...European languages, the usual ap- proach is to retain untranslatable terms unchanged (perhaps with the omission of accents or other diacritics), and named

  5. Retrieval of atmospheric methane from high spectral resolution satellite measurements: a correction for cirrus cloud effects.

    PubMed

    Bril, Andrey; Oshchepkov, Sergey; Yokota, Tatsuya

    2009-04-10

    We assessed the accuracy of methane (CH(4)) retrievals from synthetic radiance spectra particular to Greenhouse Gases Observing Satellite observations. We focused on estimating the CH(4) vertical column amount from an atmosphere that includes thin cirrus clouds, taking into account uncertain meteorological conditions. A photon path-length probability density function (PPDF)-based method was adapted to correct for atmospheric scattering effects in CH(4) retrievals. This method was shown to provide similar retrieval accuracy as compared to a carbon dioxide (CO(2))-proxy-based correction approach. It infers some advantages of PPDF-based method for methane retrievals under high variability of CO(2) abundance.

  6. Code query by example

    NASA Astrophysics Data System (ADS)

    Vaucouleur, Sebastien

    2011-02-01

    We introduce code query by example for customisation of evolvable software products in general and of enterprise resource planning systems (ERPs) in particular. The concept is based on an initial empirical study on practices around ERP systems. We motivate our design choices based on those empirical results, and we show how the proposed solution helps with respect to the infamous upgrade problem: the conflict between the need for customisation and the need for upgrade of ERP systems. We further show how code query by example can be used as a form of lightweight static analysis, to detect automatically potential defects in large software products. Code query by example as a form of lightweight static analysis is particularly interesting in the context of ERP systems: it is often the case that programmers working in this field are not computer science specialists but more of domain experts. Hence, they require a simple language to express custom rules.

  7. Query by transduction.

    PubMed

    Ho, Shen-Shyang; Wechsler, Harry

    2008-09-01

    There has been recently a growing interest in the use of transductive inference for learning. We expand here the scope of transductive inference to active learning in a stream-based setting. Towards that end this paper proposes Query-by-Transduction (QBT) as a novel active learning algorithm. QBT queries the label of an example based on the p-values obtained using transduction. We show that QBT is closely related to Query-by-Committee (QBC) using relations between transduction, Bayesian statistical testing, Kullback-Leibler divergence, and Shannon information. The feasibility and utility of QBT is shown on both binary and multi-class classification tasks using SVM as the choice classifier. Our experimental results show that QBT compares favorably, in terms of mean generalization, against random sampling, committee-based active learning, margin-based active learning, and QBC in the stream-based setting.

  8. Passage Retrieval: A Probabilistic Technique.

    ERIC Educational Resources Information Center

    Melucci, Massimo

    1998-01-01

    Presents a probabilistic technique to retrieve passages from texts having a large size or heterogeneous semantic content. Results of experiments comparing the probabilistic technique to one based on a text segmentation algorithm revealed that the passage size affects passage retrieval performance; text organization and query generality may have an…

  9. Intelligent Information Retrieval: An Introduction.

    ERIC Educational Resources Information Center

    Gauch, Susan

    1992-01-01

    Discusses the application of artificial intelligence to online information retrieval systems and describes several systems: (1) CANSEARCH, from MEDLINE; (2) Intelligent Interface for Information Retrieval (I3R); (3) Gausch's Query Reformulation; (4) Environmental Pollution Expert (EP-X); (5) PLEXUS (gardening); and (6) SCISOR (corporate…

  10. Using video objects and relevance feedback in video retrieval

    NASA Astrophysics Data System (ADS)

    Sav, Sorin; Lee, Hyowon; Smeaton, Alan F.; O'Connor, Noel E.; Murphy, Noel

    2005-10-01

    Video retrieval is mostly based on using text from dialogue and this remains the most significant component, despite progress in other aspects. One problem with this is when a searcher wants to locate video based on what is appearing in the video rather than what is being spoken about. Alternatives such as automatically-detected features and image-based keyframe matching can be used, though these still need further improvement in quality. One other modality for video retrieval is based on segmenting objects from video and allowing endusers to use these as part of querying. This uses similarity between query objects and objects from video, and in theory allows retrieval based on what is actually appearing on-screen. The main hurdles to greater use of this are the overhead of object segmentation on large amounts of video and the issue of whether we can actually achieve effective object-based retrieval. We describe a system to support object-based video retrieval where a user selects example video objects as part of the query. During a search a user builds up a set of these which are matched against objects previously segmented from a video library. This match is based on MPEG-7 Dominant Colour, Shape Compaction and Texture Browsing descriptors. We use a user-driven semi-automated segmentation process to segment the video archive which is very accurate and is faster than conventional video annotation.

  11. Cue Strength as a Moderator of the Testing Effect: The Benefits of Elaborative Retrieval

    ERIC Educational Resources Information Center

    Carpenter, Shana K.

    2009-01-01

    The current study explored the elaborative retrieval hypothesis as an explanation for the testing effect: the tendency for a memory test to enhance retention more than restudying. In particular, the retrieval process during testing may activate elaborative information related to the target response, thereby increasing the chances that activation…

  12. A Retrieved Context Account of Spacing and Repetition Effects in Free Recall

    ERIC Educational Resources Information Center

    Siegel, Lynn L.; Kahana, Michael J.

    2014-01-01

    Repeating an item in a list benefits recall performance, and this benefit increases when the repetitions are spaced apart (Madigan, 1969; Melton, 1970). Retrieved context theory incorporates 2 mechanisms that account for these effects: contextual variability and study-phase retrieval. Specifically, if an item presented at position "i" is…

  13. Effects of Immediate Testing on Delayed Retrieval: Search and Recovery Operations with Four Types of Cue

    ERIC Educational Resources Information Center

    Bartlett, James Craig

    1977-01-01

    An experiment examined the mnemonic effects of initial testing with semantic, orthographic, temporal, and recognition cues. Results were interpreted within a levels-of-processing framework in which the nature of the information used in retrieval, rather than the speed or difficulty of retrieval determines subsequent accessibility. (Editor/RK)

  14. Cue Strength as a Moderator of the Testing Effect: The Benefits of Elaborative Retrieval

    ERIC Educational Resources Information Center

    Carpenter, Shana K.

    2009-01-01

    The current study explored the elaborative retrieval hypothesis as an explanation for the testing effect: the tendency for a memory test to enhance retention more than restudying. In particular, the retrieval process during testing may activate elaborative information related to the target response, thereby increasing the chances that activation…

  15. A Retrieved Context Account of Spacing and Repetition Effects in Free Recall

    ERIC Educational Resources Information Center

    Siegel, Lynn L.; Kahana, Michael J.

    2014-01-01

    Repeating an item in a list benefits recall performance, and this benefit increases when the repetitions are spaced apart (Madigan, 1969; Melton, 1970). Retrieved context theory incorporates 2 mechanisms that account for these effects: contextual variability and study-phase retrieval. Specifically, if an item presented at position "i" is…

  16. The effect of cortisol on autobiographical memory retrieval depends on remoteness and valence of memories.

    PubMed

    Fleischer, Juliane; Weber, Juliane; Hellmann-Regen, Julian; Düsenberg, Moritz; Wolf, Oliver T; Otte, Christian; Wingenfeld, Katja

    2017-02-01

    There is evidence that specificity of autobiographical memory (AM) retrieval is impaired by cortisol. However, it is unknown whether glucocorticoids differentially influence the retrieval of recent versus remote AMs. Therefore, the aim of the current study was to investigate the effects of cortisol on AM retrieval, in terms of memory specificity, with respect to remoteness of the retrieved memories. A placebo controlled, double blind study was conducted. Thirty female and 24 male healthy participants (mean age 24.5, SD=3.7) received either placebo or 10mg hydrocortisone before completing an autobiographical memory test. Participants showed higher memory specificity for recent memories compared to remote ones. There was no main effect of cortisol on AM retrieval. However, interaction effects suggest that cortisol affects remote, but not recent memories, which seems to depend upon valence.

  17. Effects of repeated retrieval of central and peripheral details in complex emotional slides.

    PubMed

    Hauer, Beatrijs J A; Wessel, Ineke; Merckelbach, Harald; Roefs, Anne; Dalgleish, Tim

    2007-05-01

    Research has demonstrated that repeated retrieval enhances memory for practised verbal information, but undermines correct recall of unpractised related verbal information, a phenomenon known as retrieval-induced forgetting (RIF). This paper addresses the question of what happens with memory for unrehearsed aspects of an emotional picture when retrieval of other aspects of that picture is practised. In two experiments we investigated whether repeated retrieval of certain details of negative emotional slides undermines recall of unrehearsed details of such slides. In Experiment 1 retrieval of peripheral details was practised. The results demonstrated that recall for peripheral details was enhanced. However, correct recall of unpractised central details remained unaffected. Furthermore, retrieval practice did not alter the number of commission errors. Experiment 2 revealed that repeated retrieval of central details enhanced memory for these details. Although more commission errors were produced, again correct recall was not impaired for the unrehearsed central and peripheral details. This failure to find retrieval-induced forgetting effects for complex visual material is at odds with the RIF literature, and potential reasons for this are discussed. The data also extend previous studies in demonstrating that extensive retrieval can increase the number of commission errors.

  18. Influence of retrieval mode on effects of production: Evidence for costs in free recall.

    PubMed

    Mama, Yaniv; Icht, Michal

    2016-06-01

    Study modality (visual, auditory) of words as well as production mode (reading aloud, writing down) have been shown to influence the production effect (PE). When study words are presented visually, reading them aloud yields superior memory. However, when the same study words are presented aurally, writing them down leads to superior memory. Missing in PE studies is the variable of retrieval mode (written, aloud), which was addressed in the present study. In a pair of experiments, we manipulated the 3 variables-study modality, production mode, and retrieval mode-in a factorial fashion. With visual study, aloud production mode (vocalizing) was found to be superior to written production, in both retrieval modes (written and aloud). However, the difference between the productions was significantly smaller in the aloud retrieval mode relative to the written retrieval mode. With auditory study, written production mode was superior to aloud production mode, in the written as well as in the aloud retrieval modes. Here, the difference between the productions was significantly smaller in the written relative to the aloud retrieval mode. In other words, the difference between productions was smaller for the retrieval mode that matched the superior production. We interpret these findings using a retrieval-cost account. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  19. Measured space environmental effects to LDEF during retrieval

    NASA Technical Reports Server (NTRS)

    Maag, Carl R.; Linder, W. Kelly

    1992-01-01

    On the STS-32 shuttle mission, a space flight experiment provided an understanding of the effects of the space environment on the Long Duration Exposure Facility (LDEF) from rendezvous with the shuttle until removal from the payload bay at the Orbiter Processing Facility (OPF) at KSC. The Interim Operational Contamination Monitor (IOCM) is an attached shuttle payload that has been used on two earlier flights (STS 51C and STS 28) to quantify the contamination deposited during the course of the mission. The IOCM can characterize by direct measurement, the deposition of molecular and particulate contamination during any phase of flight. In addition to these principal measurements, the IOCM actively measures the thermophysical properties of thermal control surfaces by calorimetry, the flux of the ambient atomic oxygen environment, the incident solar flux, and the absolute ambient pressure in the payload bay. The IOCM also provides a structure and sample holders for the exposure of passive material samples to the space environment, e.g. thermal cycling, atomic oxygen, and micrometeoroids and/or orbital debris, etc. One of the more salient results from the STS-32 flight suggests that the LDEF emitted a large number of particulates after berthing into the shuttle. The mission atomic oxygen fluence was also calculated. Although the fluence was low by normal standards, the Kapton passive samples exhibited the onset of erosion. Orbital debris and micrometeoroid impacts also occurred during the retrieval mission. The average perforation diameter was approximately 12.5 microns. The largest perforation diameter was measured at 65 microns.

  20. Mood-state-dependent retrieval: the effects of induced mood on memory reconsidered.

    PubMed

    Kenealy, P M

    1997-05-01

    Analysis of studies investigating mood-state-dependent retrieval identifies methodological problems that may have contributed to the controversy surrounding the reliability of the effect-in particular, the possible confounding of encoding and retrieval in previous studies. Five experiments are reported investigating the effects of mood on learning and recall. Mood-state-dependent retrieval was observed in Experiment 1a (using Velten's Mood Induction Procedure); Experiment 1b (using a music MIP); and Experiment lc (using Velten's MIP at encoding and a music MIP at retrieval). Subjects who learned and recalled in different moods had significantly greater decrements in recall than did subjects in the same moods. Experiments 2 and 3 investigated the effect of observable retrieval cues on mood-state-dependent retrieval. In Experiment 2, the presence of observable retrieval cues at recall overrode state-dependent retrieval. In Experiment 3, by manipulating the presence or absence of observable cues at recall, both the occurrence and the erasure of the mood-state dependency was demonstrated. Mood state during learning and cued recall was also shown to affect performance in a third session under conditions of free recall.

  1. FRS EZ Query

    EPA Pesticide Factsheets

    This page is the starting point for EZ Query. This page describes how to select key data elements from EPA's Facility Information Database and Geospatial Reference Database to build a tabular report or a Comma Separated Value (CSV) files for downloading.

  2. Query Support for Gmz

    NASA Astrophysics Data System (ADS)

    Khandelwal, A.; Rajan, K. S.

    2017-07-01

    Generic text-based compression models are simple and fast but there are two issues that needs to be addressed. They cannot leverage the structure that exists in data to achieve better compression and there is an unnecessary decompression step before the user can actually use the data. To address these issues, we came up with GMZ, a lossless compression model aimed at achieving high compression ratios. The decision to design GMZ (Khandelwal and Rajan, 2017) exclusively for GML's Simple Features Profile (SFP) seems fair because of the high use of SFP in WFS and that it facilitates high optimisation of the compression model. This is an extension of our work on GMZ. In a typical server-client model such as Web Feature Service, the server is the primary creator and provider of GML, and therefore, requires compression and query capabilities. On the other hand, the client is the primary consumer of GML, and therefore, requires decompression and visualisation capabilities. In the first part of our work, we demonstrated compression using a python script that can be plugged in a server architecture, and decompression and visualisation in a web browser using a Firefox addon. The focus of this work is to develop the already existing tools to provide query capability to server. Our model provides the ability to decompress individual features in isolation, which is an essential requirement for realising query in compressed state. We con - struct an R-Tree index for spatial data and a custom index for non-spatial data and store these in a separate index file to prevent alter - ing the compression model. This facilitates independent use of compressed GMZ file where index can be constructed when required. The focus of this work is the bounding-box or range query commonly used in webGIS with provision for other spatial and non-spatial queries. The decrement in compression ratios due to the new index file is in the range of 1-3 percent which is trivial considering the benefits of

  3. The Effects of Prohibiting Gestures on Children's Lexical Retrieval Ability

    ERIC Educational Resources Information Center

    Pine, Karen J.; Bird, Hannah; Kirk, Elizabeth

    2007-01-01

    Two alternative accounts have been proposed to explain the role of gestures in thinking and speaking. The Information Packaging Hypothesis (Kita, 2000) claims that gestures are important for the conceptual packaging of information before it is coded into a linguistic form for speech. The Lexical Retrieval Hypothesis (Rauscher, Krauss & Chen, 1996)…

  4. The Effect of Semantic Representation on Toddlers' Word Retrieval

    ERIC Educational Resources Information Center

    Capone, Nina C.; McGregor, Karla K.

    2005-01-01

    Purpose: This study tested the hypothesis that depth of semantic representation influences toddlers' word retrieval. Method: Nineteen toddlers participated under 3 word learning conditions in this longitudinal study. Gestures cued attention to object shape (SHP) or function (FNC) in the experimental conditions. No semantic cue was provided under a…

  5. The Effects of Prohibiting Gestures on Children's Lexical Retrieval Ability

    ERIC Educational Resources Information Center

    Pine, Karen J.; Bird, Hannah; Kirk, Elizabeth

    2007-01-01

    Two alternative accounts have been proposed to explain the role of gestures in thinking and speaking. The Information Packaging Hypothesis (Kita, 2000) claims that gestures are important for the conceptual packaging of information before it is coded into a linguistic form for speech. The Lexical Retrieval Hypothesis (Rauscher, Krauss & Chen, 1996)…

  6. Natural language information retrieval in digital libraries

    SciTech Connect

    Strzalkowski, T.; Perez-Carballo, J.; Marinescu, M.

    1996-12-31

    In this paper we report on some recent developments in joint NYU and GE natural language information retrieval system. The main characteristic of this system is the use of advanced natural language processing to enhance the effectiveness of term-based document retrieval. The system is designed around a traditional statistical backbone consisting of the indexer module, which builds inverted index files from pre-processed documents, and a retrieval engine which searches and ranks the documents in response to user queries. Natural language processing is used to (1) preprocess the documents in order to extract content-carrying terms, (2) discover inter-term dependencies and build a conceptual hierarchy specific to the database domain, and (3) process user`s natural language requests into effective search queries. This system has been used in NIST-sponsored Text Retrieval Conferences (TREC), where we worked with approximately 3.3 GBytes of text articles including material from the Wall Street Journal, the Associated Press newswire, the Federal Register, Ziff Communications`s Computer Library, Department of Energy abstracts, U.S. Patents and the San Jose Mercury News, totaling more than 500 million words of English. The system have been designed to facilitate its scalability to deal with ever increasing amounts of data. In particular, a randomized index-splitting mechanism has been installed which allows the system to create a number of smaller indexes that can be independently and efficiently searched.

  7. Stress effects on declarative memory retrieval are blocked by a beta-adrenoceptor antagonist in humans.

    PubMed

    Schwabe, Lars; Römer, Sonja; Richter, Steffen; Dockendorf, Svenja; Bilak, Boris; Schächinger, Hartmut

    2009-04-01

    Previous evidence indicates that stress hormone effects on memory consolidation depend on concurrent emotional arousal-induced noradrenergic activity. Here, we asked whether this is also true for stress effects on memory retrieval and hypothesized that administration of the beta-adrenoceptor antagonist propranolol would block the effects of stress on declarative and procedural retrieval performance. In a double-blind, placebo-controlled, crossover study, 44 healthy young men learned a list of emotional and neutral words (declarative memory task) and completed a serial reaction time task (procedural memory task). On the following day, participants received either a placebo or 40 mg propranolol orally. One hour later, they were exposed to stress (socially evaluated cold pressor test (SECPT)) or a control condition 30 min prior to retention testing. Stress selectively enhanced the retrieval of emotionally arousing words. Pretreatment with propranolol had no effect on memory alone but blocked the stress-induced memory enhancement for emotional words, confirming the importance of noradrenergic activity in stress effects on memory retrieval. Memory for neutral words and the procedural task was neither affected by stress nor by propranolol. The present findings suggest that stress (hormone) effects on emotional memory retrieval require concurrent noradrenergic activation. Procedural memory retrieval and the retrieval of neutral verbal material appear to be less susceptible to stress.

  8. A retrieved context account of spacing and repetition effects in free recall

    PubMed Central

    Lohnas, Lynn J.; Kahana, Michael J.

    2014-01-01

    Repeating an item in a list benefits recall performance, and this benefit increases when the repetitions are spaced apart (Madigan, 1969; Melton, 1970). Retrieved context theory incorporates two mechanisms that account for these effects: contextual variability and study-phase retrieval. Specifically, if an item presented at position i is repeated at position j, this leads to retrieval of its context from its initial presentation at i (study-phase retrieval) and this retrieved context will be used to update the current state of context (contextual variability). Here we consider predictions of a computational model that embodies retrieved context theory, the context maintenance and retrieval model (CMR; Polyn, Norman, & Kahana, 2009). CMR makes the novel prediction that subjects are more likely to successively recall items that follow a shared repeated item (e.g. i + 1, j + 1) because both items are associated with the context of the repeated item presented at i and j. CMR also predicts that the probability of recalling at least one of two studied items should increase with the items’ spacing (Lohnas, Polyn, & Kahana, 2011). We tested these predictions in a new experiment and CMR’s predictions were upheld. These findings suggest that retrieved context theory offers an integrated explanation for repetition and spacing effects in free recall tasks. PMID:24564545

  9. A Query Integrator and Manager for the Query Web

    PubMed Central

    Brinkley, James F.; Detwiler, Landon T.

    2012-01-01

    We introduce two concepts: the Query Web as a layer of interconnected queries over the document web and the semantic web, and a Query Web Integrator and Manager (QI) that enables the Query Web to evolve. QI permits users to write, save and reuse queries over any web accessible source, including other queries saved in other installations of QI. The saved queries may be in any language (e.g. SPARQL, XQuery); the only condition for interconnection is that the queries return their results in some form of XML. This condition allows queries to chain off each other, and to be written in whatever language is appropriate for the task. We illustrate the potential use of QI for several biomedical use cases, including ontology view generation using a combination of graph-based and logical approaches, value set generation for clinical data management, image annotation using terminology obtained from an ontology web service, ontology-driven brain imaging data integration, small-scale clinical data integration, and wider-scale clinical data integration. Such use cases illustrate the current range of applications of QI and lead us to speculate about the potential evolution from smaller groups of interconnected queries into a larger query network that layers over the document and semantic web. The resulting Query Web could greatly aid researchers and others who now have to manually navigate through multiple information sources in order to answer specific questions. PMID:22531831

  10. A query integrator and manager for the query web.

    PubMed

    Brinkley, James F; Detwiler, Landon T

    2012-10-01

    We introduce two concepts: the Query Web as a layer of interconnected queries over the document web and the semantic web, and a Query Web Integrator and Manager (QI) that enables the Query Web to evolve. QI permits users to write, save and reuse queries over any web accessible source, including other queries saved in other installations of QI. The saved queries may be in any language (e.g. SPARQL, XQuery); the only condition for interconnection is that the queries return their results in some form of XML. This condition allows queries to chain off each other, and to be written in whatever language is appropriate for the task. We illustrate the potential use of QI for several biomedical use cases, including ontology view generation using a combination of graph-based and logical approaches, value set generation for clinical data management, image annotation using terminology obtained from an ontology web service, ontology-driven brain imaging data integration, small-scale clinical data integration, and wider-scale clinical data integration. Such use cases illustrate the current range of applications of QI and lead us to speculate about the potential evolution from smaller groups of interconnected queries into a larger query network that layers over the document and semantic web. The resulting Query Web could greatly aid researchers and others who now have to manually navigate through multiple information sources in order to answer specific questions.

  11. Efficient view based 3-D object retrieval using Hidden Markov Model

    NASA Astrophysics Data System (ADS)

    Jain, Yogendra Kumar; Singh, Roshan Kumar

    2013-12-01

    Recent research effort has been dedicated to view based 3-D object retrieval, because of highly discriminative property of 3-D object and has multi view representation. The state-of-art method is highly depending on their own camera array setting for capturing views of 3-D object and use complex Zernike descriptor, HAC for representative view selection which limit their practical application and make it inefficient for retrieval. Therefore, an efficient and effective algorithm is required for 3-D Object Retrieval. In order to move toward a general framework for efficient 3-D object retrieval which is independent of camera array setting and avoidance of representative view selection, we propose an Efficient View Based 3-D Object Retrieval (EVBOR) method using Hidden Markov Model (HMM). In this framework, each object is represented by independent set of view, which means views are captured from any direction without any camera array restriction. In this, views are clustered (including query view) to generate the view cluster, which is then used to build the query model with HMM. In our proposed method, HMM is used in twofold: in the training (i.e. HMM estimate) and in the retrieval (i.e. HMM decode). The query model is trained by using these view clusters. The EVBOR query model is worked on the basis of query model combining with HMM. The proposed approach remove statically camera array setting for view capturing and can be apply for any 3-D object database to retrieve 3-D object efficiently and effectively. Experimental results demonstrate that the proposed scheme has shown better performance than existing methods. [Figure not available: see fulltext.

  12. Spoken Document Retrieval Leveraging Unsupervised and Supervised Topic Modeling Techniques

    NASA Astrophysics Data System (ADS)

    Chen, Kuan-Yu; Wang, Hsin-Min; Chen, Berlin

    This paper describes the application of two attractive categories of topic modeling techniques to the problem of spoken document retrieval (SDR), viz. document topic model (DTM) and word topic model (WTM). Apart from using the conventional unsupervised training strategy, we explore a supervised training strategy for estimating these topic models, imagining a scenario that user query logs along with click-through information of relevant documents can be utilized to build an SDR system. This attempt has the potential to associate relevant documents with queries even if they do not share any of the query words, thereby improving on retrieval quality over the baseline system. Likewise, we also study a novel use of pseudo-supervised training to associate relevant documents with queries through a pseudo-feedback procedure. Moreover, in order to lessen SDR performance degradation caused by imperfect speech recognition, we investigate leveraging different levels of index features for topic modeling, including words, syllable-level units, and their combination. We provide a series of experiments conducted on the TDT (TDT-2 and TDT-3) Chinese SDR collections. The empirical results show that the methods deduced from our proposed modeling framework are very effective when compared with a few existing retrieval approaches.

  13. Multidimensional indexing structure for use with linear optimization queries

    NASA Technical Reports Server (NTRS)

    Bergman, Lawrence David (Inventor); Castelli, Vittorio (Inventor); Chang, Yuan-Chi (Inventor); Li, Chung-Sheng (Inventor); Smith, John Richard (Inventor)

    2002-01-01

    Linear optimization queries, which usually arise in various decision support and resource planning applications, are queries that retrieve top N data records (where N is an integer greater than zero) which satisfy a specific optimization criterion. The optimization criterion is to either maximize or minimize a linear equation. The coefficients of the linear equation are given at query time. Methods and apparatus are disclosed for constructing, maintaining and utilizing a multidimensional indexing structure of database records to improve the execution speed of linear optimization queries. Database records with numerical attributes are organized into a number of layers and each layer represents a geometric structure called convex hull. Such linear optimization queries are processed by searching from the outer-most layer of this multi-layer indexing structure inwards. At least one record per layer will satisfy the query criterion and the number of layers needed to be searched depends on the spatial distribution of records, the query-issued linear coefficients, and N, the number of records to be returned. When N is small compared to the total size of the database, answering the query typically requires searching only a small fraction of all relevant records, resulting in a tremendous speedup as compared to linearly scanning the entire dataset.

  14. Working memory capacity predicts the beneficial effect of selective memory retrieval.

    PubMed

    Schlichting, Andreas; Aslan, Alp; Holterman, Christoph; Bäuml, Karl-Heinz T

    2015-01-01

    Selective retrieval of some studied items can both impair and improve recall of the other items. This study examined the role of working memory capacity (WMC) for the two effects of memory retrieval. Participants studied an item list consisting of predefined target and nontarget items. After study of the list, half of the participants performed an imagination task supposed to induce a change in mental context, whereas the other half performed a counting task which does not induce such context change. Following presentation of a second list, memory for the original list's target items was tested, either with or without preceding retrieval of the list's nontarget items. Consistent with previous work, preceding nontarget retrieval impaired target recall in the absence of the context change, but improved target recall in its presence. In particular, there was a positive relationship between WMC and the beneficial, but not the detrimental effect of memory retrieval. On the basis of the view that the beneficial effect of memory retrieval reflects context-reactivation processes, the results indicate that individuals with higher WMC are better able to capitalise on retrieval-induced context reactivation than individuals with lower WMC.

  15. A Semantic Graph Query Language

    SciTech Connect

    Kaplan, I L

    2006-10-16

    Semantic graphs can be used to organize large amounts of information from a number of sources into one unified structure. A semantic query language provides a foundation for extracting information from the semantic graph. The graph query language described here provides a simple, powerful method for querying semantic graphs.

  16. Cortisol has enhancing, rather than impairing effects on memory retrieval in PTSD.

    PubMed

    Wingenfeld, Katja; Driessen, Martin; Terfehr, Kirsten; Schlosser, Nicole; Fernando, Silvia Carvalho; Otte, Christian; Beblo, Thomas; Spitzer, Carsten; Löwe, Bernd; Wolf, Oliver Tobias

    2012-07-01

    In the present study, we aimed to compare the effect of exogenous cortisol on memory retrieval in posttraumatic stress disorder (PTSD) with the effects in healthy controls. In healthy participants, administration of cortisol impairs declarative memory retrieval. Only a few studies have investigated these effects in PTSD yielding mixed results. In a placebo-controlled crossover study, 44 patients with PTSD and 65 healthy controls received either placebo or 10mg of hydrocortisone orally before memory testing. In addition to declarative memory retrieval (word list learning), we also tested autobiographical memory retrieval specificity. In both tasks opposing effects of cortisol on memory were observed when comparing patients with controls. In controls, cortisol had impairing effects on memory retrieval, while in PTSD patients cortisol had enhancing effects on memory retrieval in both memory domains. The present results suggest beneficial effects of acute cortisol elevations on hippocampal mediated memory processes in PTSD. Possible neurobiological mechanisms underlying these findings are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Impact of Three-Dimensional Radiative Effects on Satellite Retrievals of Cloud Droplet Sizes

    NASA Technical Reports Server (NTRS)

    Marshak, Alexander; Platnick, Steven; Varnai, Tamas; Wen, Guoyong; Cahalan, Robert F.

    2006-01-01

    There are several dozen papers that study the effects of cloud horizontal inhomogeneity on the retrievals of cloud optical thickness, but only a few of them deal with cloud droplet sizes. This paper is one of the first comprehensive attempts to fill this gap: It takes a close theoretical look at the radiative effects of cloud 3-D structure in retrievals of droplet effective radii. Under some general assumptions, it was found that ignoring subpixel (unresolved) variability produces a negative bias in the retrieved effective radius, while ignoring cloud inhomogeneity at scales larger than a pixel scale (resolved variability), on the contrary, leads to overestimation of the domain average droplet size. The theoretical results are illustrated with examples from Large Eddy Simulations (LES) of cumulus (Cu) and stratocumulus (Sc) cloud fields. The analysis of cloud drop size distributions retrieved from both LES fields confirms that ignoring shadowing in 1-D retrievals results in substantial overestimation of effective radii which is more pronounced for broken Cu than for Sc clouds. Collocated measurements of broken Cu clouds by Moderate Resolution Imaging Spectrometer (MODIS) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) are used to check simulations and theory with observations. The analysis of ASTER and MODIS data and associated derived products recommends against blindly using retrieved effective radii for broken cloud fields, especially if one wants to relate aerosol amounts to cloud droplet sizes.

  18. Effect of Tropospheric Aerosols in Satellite-Based Trace Gas Retrieval

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay; Torres, Omar; Yang, Kai; Vassilkov, Alexander

    2011-01-01

    Scattering and absorption by tropospheric aerosol particles have an effect on the airmass factor (AMF), a fundamental quantity for trace gas concentration retrieval by inversion of satellite measurements. The interference effect depends on the aerosols micro-physical and optical properties as well as the relative distribution of the tropospheric trace gas and aerosol load. Quantifying the aerosol impact on trace gas retrieval requires a sensitivity study using radiative transfer calculations. In this presentation we will describe a recently initiated effort to characterize the aerosol-related error in trace gas retrievals when the presence of aerosol particles is not accounted in the inversion procedure. A general description of the project will be presented and preliminary results on aerosol effects on SO2 retrieved concentrations will be discussed.

  19. Web Image Re-Ranking UsingQuery-Specific Semantic Signatures.

    PubMed

    Wang, Xiaogang; Qiu, Shi; Liu, Ke; Tang, Xiaoou

    2014-04-01

    Image re-ranking, as an effective way to improve the results of web-based image search, has been adopted by current commercial search engines such as Bing and Google. Given a query keyword, a pool of images are first retrieved based on textual information. By asking the user to select a query image from the pool, the remaining images are re-ranked based on their visual similarities with the query image. A major challenge is that the similarities of visual features do not well correlate with images' semantic meanings which interpret users' search intention. Recently people proposed to match images in a semantic space which used attributes or reference classes closely related to the semantic meanings of images as basis. However, learning a universal visual semantic space to characterize highly diverse images from the web is difficult and inefficient. In this paper, we propose a novel image re-ranking framework, which automatically offline learns different semantic spaces for different query keywords. The visual features of images are projected into their related semantic spaces to get semantic signatures. At the online stage, images are re-ranked by comparing their semantic signatures obtained from the semantic space specified by the query keyword. The proposed query-specific semantic signatures significantly improve both the accuracy and efficiency of image re-ranking. The original visual features of thousands of dimensions can be projected to the semantic signatures as short as 25 dimensions. Experimental results show that 25-40 percent relative improvement has been achieved on re-ranking precisions compared with the state-of-the-art methods.

  20. Image Retrieval: Theoretical Analysis and Empirical User Studies on Accessing Information in Images.

    ERIC Educational Resources Information Center

    Ornager, Susanne

    1997-01-01

    Discusses indexing and retrieval for effective searches of digitized images. Reports on an empirical study about criteria for analysis and indexing digitized images, and the different types of user queries done in newspaper image archives in Denmark. Concludes that it is necessary that the indexing represent both a factual and an expressional…

  1. A Spoken Access Approach for Chinese Text and Speech Information Retrieval.

    ERIC Educational Resources Information Center

    Chien, Lee-Feng; Wang, Hsin-Min; Bai, Bo-Ren; Lin, Sun-Chein

    2000-01-01

    Presents an efficient spoken-access approach for both Chinese text and Mandarin speech information retrieval. Highlights include human-computer interaction via voice input, speech query recognition at the syllable level, automatic term suggestion, relevance feedback techniques, and experiments that show an improvement in the effectiveness of…

  2. Image Retrieval: Theoretical Analysis and Empirical User Studies on Accessing Information in Images.

    ERIC Educational Resources Information Center

    Ornager, Susanne

    1997-01-01

    Discusses indexing and retrieval for effective searches of digitized images. Reports on an empirical study about criteria for analysis and indexing digitized images, and the different types of user queries done in newspaper image archives in Denmark. Concludes that it is necessary that the indexing represent both a factual and an expressional…

  3. PRoSPer: perceptual similarity queries in medical CBIR systems through user profiles.

    PubMed

    Bugatti, Pedro H; Kaster, Daniel S; Ponciano-Silva, Marcelo; Traina, Caetano; Azevedo-Marques, Paulo M; Traina, Agma J M

    2014-02-01

    In this paper, we present a novel approach to perform similarity queries over medical images, maintaining the semantics of a given query posted by the user. Content-based image retrieval systems relying on relevance feedback techniques usually request the users to label relevant/irrelevant images. Thus, we present a highly effective strategy to survey user profiles, taking advantage of such labeling to implicitly gather the user perceptual similarity. The profiles maintain the settings desired for each user, allowing tuning of the similarity assessment, which encompasses the dynamic change of the distance function employed through an interactive process. Experiments on medical images show that the method is effective and can improve the decision making process during analysis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. An Evaluation of Multiple Query Representations for the Relevance Judgments used to Build a Biomedical Test Collection.

    PubMed

    Ryu, Borim; Choi, Jinwook

    2012-03-01

    The purpose of this study is to validate a method that uses multiple queries to create a set of relevance judgments used to indicate which documents are pertinent to each query when forming a biomedical test collection. The aspect query is the major concept of this research; it can represent every aspect of the original query with the same informational need. Manually generated aspect queries created by 15 recruited participants where run using the BM25 retrieval model in order to create aspect query based relevance sets (QRELS). In order to demonstrate the feasibility of these QRELSs, The results from a 2004 genomics track run supported by the National Institute of Standards and Technology (NIST) were used to compute the mean average precision (MAP) based on Text Retrieval Conference (TREC) QRELSs and aspect-QRELSs. The rank correlation was calculated using both Kendall's and Spearman's rank correlation methods. We experimentally verified the utility of the aspect query method by combining the top ranked documents retrieved by a number of multiple queries which ranked the order of the information. The retrieval system correlated highly with rankings based on human relevance judgments. Substantial results were shown with high correlations of up to 0.863 (p < 0.01) between the judgment-free gold standard based on the aspect queries and the human-judged gold standard supported by NIST. The results also demonstrate that the aspect query method can contribute in building test collections used for medical literature retrieval.

  5. Integration of Complex Objects and Transitive Relationships for Information Retrieval.

    ERIC Educational Resources Information Center

    Jarvelin, Kalervo; Niemi, Timo

    1999-01-01

    Shows that in advanced information-retrieval applications capabilities for data aggregation, transitive computation and non-first normal-form relational computation are often necessary at the same time. Topics include complex objects; advanced data models; query languages; query formulation; knowledge representation; and query-language syntax.…

  6. Aerosol scattering effects on water vapor retrievals over the Los Angeles Basin

    NASA Astrophysics Data System (ADS)

    Zeng, Zhao-Cheng; Zhang, Qiong; Natraj, Vijay; Margolis, Jack S.; Shia, Run-Lie; Newman, Sally; Fu, Dejian; Pongetti, Thomas J.; Wong, Kam W.; Sander, Stanley P.; Wennberg, Paul O.; Yung, Yuk L.

    2017-02-01

    In this study, we propose a novel approach to describe the scattering effects of atmospheric aerosols in a complex urban environment using water vapor (H2O) slant column measurements in the near infrared. This approach is demonstrated using measurements from the California Laboratory for Atmospheric Remote Sensing Fourier Transform Spectrometer on the top of Mt. Wilson, California, and a two-stream-exact single scattering (2S-ESS) radiative transfer (RT) model. From the spectral measurements, we retrieve H2O slant column density (SCD) using 15 different absorption bands between 4000 and 8000 cm-1. Due to the wavelength dependence of aerosol scattering, large variations in H2O SCD retrievals are observed as a function of wavelength. Moreover, the variations are found to be correlated with aerosol optical depths (AODs) measured at the AERONET-Caltech station. Simulation results from the RT model reproduce this correlation and show that the aerosol scattering effect is the primary contributor to the variations in the wavelength dependence of the H2O SCD retrievals. A significant linear correlation is also found between variations in H2O SCD retrievals from different bands and corresponding AOD data; this correlation is associated with the asymmetry parameter, which is a first-order measure of the aerosol scattering phase function. The evidence from both measurements and simulations suggests that wavelength-dependent aerosol scattering effects can be derived using H2O retrievals from multiple bands. This understanding of aerosol scattering effects on H2O retrievals suggests a promising way to quantify the effect of aerosol scattering on greenhouse gas retrievals and could potentially contribute towards reducing biases in greenhouse gas retrievals from space.

  7. Retrievals of cloud optical depth and effective radius from Thin-Cloud Rotating Shadowband Radiometer measurements

    SciTech Connect

    Yin B.; Vogelmann A.; Min Q.; Duan M.; Bartholomew M. J.; Turner D. D.

    2011-12-13

    A Thin-Cloud Rotating Shadowband Radiometer (TCRSR) was developed and deployed in a field test at the Atmospheric Radiation Measurement Climate Research Facility's Southern Great Plains site. The TCRSR measures the forward-scattering lobe of the direct solar beam (i.e., the solar aureole) through an optically thin cloud (optical depth < 8). We applied the retrieval algorithm of Min and Duan (2005) to the TCRSR measurements of the solar aureole to derive simultaneously the cloud optical depth (COD) and cloud drop effective radius (DER), subsequently inferring the cloud liquid-water path (LWP). After careful calibration and preprocessing, our results indicate that the TCRSR is able to retrieve simultaneously these three properties for optically thin water clouds. Colocated instruments, such as the MultiFilter Rotating Shadowband Radiometer (MFRSR), atmospheric emitted radiance interferometer (AERI), and Microwave Radiometer (MWR), are used to evaluate our retrieval results. The relative difference between retrieved CODs from the TCRSR and those from the MFRSR is less than 5%. The distribution of retrieved LWPs from the TCRSR is similar to those from the MWR and AERI. The differences between the TCRSR-based retrieved DERs and those from the AERI are apparent in some time periods, and the uncertainties of the DER retrievals are discussed in detail in this article.

  8. Analysis of PubMed User Sessions Using a Full-Day PubMed Query Log: A Comparison of Experienced and Nonexperienced PubMed Users

    PubMed Central

    2015-01-01

    Background PubMed is the largest biomedical bibliographic information source on the Internet. PubMed has been considered one of the most important and reliable sources of up-to-date health care evidence. Previous studies examined the effects of domain expertise/knowledge on search performance using PubMed. However, very little is known about PubMed users’ knowledge of information retrieval (IR) functions and their usage in query formulation. Objective The purpose of this study was to shed light on how experienced/nonexperienced PubMed users perform their search queries by analyzing a full-day query log. Our hypotheses were that (1) experienced PubMed users who use system functions quickly retrieve relevant documents and (2) nonexperienced PubMed users who do not use them have longer search sessions than experienced users. Methods To test these hypotheses, we analyzed PubMed query log data containing nearly 3 million queries. User sessions were divided into two categories: experienced and nonexperienced. We compared experienced and nonexperienced users per number of sessions, and experienced and nonexperienced user sessions per session length, with a focus on how fast they completed their sessions. Results To test our hypotheses, we measured how successful information retrieval was (at retrieving relevant documents), represented as the decrease rates of experienced and nonexperienced users from a session length of 1 to 2, 3, 4, and 5. The decrease rate (from a session length of 1 to 2) of the experienced users was significantly larger than that of the nonexperienced groups. Conclusions Experienced PubMed users retrieve relevant documents more quickly than nonexperienced PubMed users in terms of session length. PMID:26139516

  9. An Analysis of Web Image Queries for Search.

    ERIC Educational Resources Information Center

    Pu, Hsiao-Tieh

    2003-01-01

    Examines the differences between Web image and textual queries, and attempts to develop an analytic model to investigate their implications for Web image retrieval systems. Provides results that give insight into Web image searching behavior and suggests implications for improvement of current Web image search engines. (AEF)

  10. Observations of Three-Dimensional Radiative Effects that Influence Satellite Retrievals of Cloud Properties

    NASA Technical Reports Server (NTRS)

    Varnai, Tamas; Marshak, Alexander; Lau, William K. M. (Technical Monitor)

    2001-01-01

    This paper examines three-dimensional (3D) radiative effects, which arise from horizontal radiative interactions between areas that have different cloud properties. Earlier studies have argued that these effects can cause significant uncertainties in current satellite retrievals of cloud properties, because the retrievals rely on one-dimensional (1D) theory and do not consider the effects of horizontal changes in cloud properties. This study addresses two questions: which retrieved cloud properties are influenced by 3D radiative effects, and where 3D effects tend to occur? The influence of 3D effects is detected from the wayside illumination and shadowing make clouds appear asymmetric: Areas appear brighter if the cloud top surface is tilted toward, rather than away from, the Sun. The analysis of 30 images by the Moderate Resolution Imaging Spectroradiometer (MODIS) reveals that retrievals of cloud optical thickness and cloud water content are most influenced by 3D effects, whereas retrievals of cloud particle size are much less affected. The results also indicate that while 3D effects are strongest at cloud edges, cloud top variability in cloud interiors, even in overcast regions, also produces considerable 3D effects. Finally, significant 3D effects are found in a wide variety of situations, ranging from thin clouds to thick ones and from low clouds to high ones.

  11. Intelligent web image retrieval system

    NASA Astrophysics Data System (ADS)

    Hong, Sungyong; Lee, Chungwoo; Nah, Yunmook

    2001-07-01

    Recently, the web sites such as e-business sites and shopping mall sites deal with lots of image information. To find a specific image from these image sources, we usually use web search engines or image database engines which rely on keyword only retrievals or color based retrievals with limited search capabilities. This paper presents an intelligent web image retrieval system. We propose the system architecture, the texture and color based image classification and indexing techniques, and representation schemes of user usage patterns. The query can be given by providing keywords, by selecting one or more sample texture patterns, by assigning color values within positional color blocks, or by combining some or all of these factors. The system keeps track of user's preferences by generating user query logs and automatically add more search information to subsequent user queries. To show the usefulness of the proposed system, some experimental results showing recall and precision are also explained.

  12. Semantic concept-enriched dependence model for medical information retrieval.

    PubMed

    Choi, Sungbin; Choi, Jinwook; Yoo, Sooyoung; Kim, Heechun; Lee, Youngho

    2014-02-01

    In medical information retrieval research, semantic resources have been mostly used by expanding the original query terms or estimating the concept importance weight. However, implicit term-dependency information contained in semantic concept terms has been overlooked or at least underused in most previous studies. In this study, we incorporate a semantic concept-based term-dependence feature into a formal retrieval model to improve its ranking performance. Standardized medical concept terms used by medical professionals were assumed to have implicit dependency within the same concept. We hypothesized that, by elaborately revising the ranking algorithms to favor documents that preserve those implicit dependencies, the ranking performance could be improved. The implicit dependence features are harvested from the original query using MetaMap. These semantic concept-based dependence features were incorporated into a semantic concept-enriched dependence model (SCDM). We designed four different variants of the model, with each variant having distinct characteristics in the feature formulation method. We performed leave-one-out cross validations on both a clinical document corpus (TREC Medical records track) and a medical literature corpus (OHSUMED), which are representative test collections in medical information retrieval research. Our semantic concept-enriched dependence model consistently outperformed other state-of-the-art retrieval methods. Analysis shows that the performance gain has occurred independently of the concept's explicit importance in the query. By capturing implicit knowledge with regard to the query term relationships and incorporating them into a ranking model, we could build a more robust and effective retrieval model, independent of the concept importance. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. An end user evaluation of query formulation and results review tools in three medical meta-search engines.

    PubMed

    Leroy, Gondy; Xu, Jennifer; Chung, Wingyan; Eggers, Shauna; Chen, Hsinchun

    2007-01-01

    Retrieving sufficient relevant information online is difficult for many people because they use too few keywords to search and search engines do not provide many support tools. To further complicate the search, users often ignore support tools when available. Our goal is to evaluate in a realistic setting when users use support tools and how they perceive these tools. We compared three medical search engines with support tools that require more or less effort from users to form a query and evaluate results. We carried out an end user study with 23 users who were asked to find information, i.e., subtopics and supporting abstracts, for a given theme. We used a balanced within-subjects design and report on the effectiveness, efficiency and usability of the support tools from the end user perspective. We found significant differences in efficiency but did not find significant differences in effectiveness between the three search engines. Dynamic user support tools requiring less effort led to higher efficiency. Fewer searches were needed and more documents were found per search when both query reformulation and result review tools dynamically adjust to the user query. The query reformulation tool that provided a long list of keywords, dynamically adjusted to the user query, was used most often and led to more subtopics. As hypothesized, the dynamic result review tools were used more often and led to more subtopics than static ones. These results were corroborated by the usability questionnaires, which showed that support tools that dynamically optimize output were preferred.

  14. Queries for Bias Testing

    NASA Technical Reports Server (NTRS)

    Gordon, Diana F.

    1992-01-01

    Selecting a good bias prior to concept learning can be difficult. Therefore, dynamic bias adjustment is becoming increasingly popular. Current dynamic bias adjustment systems, however, are limited in their ability to identify erroneous assumptions about the relationship between the bias and the target concept. Without proper diagnosis, it is difficult to identify and then remedy faulty assumptions. We have developed an approach that makes these assumptions explicit, actively tests them with queries to an oracle, and adjusts the bias based on the test results.

  15. Robust Quantum Private Queries

    NASA Astrophysics Data System (ADS)

    Wang, Tian-Yin; Wang, Shu-Yu; Ma, Jian-Feng

    2016-07-01

    We propose a new quantum private query protocol with the technique of decoherence-free states, which is a theoretical study of how decoherence-free states can be used for the protection of quantum information in such a protocol. This protocol can solve the noise problem that will make the user obtain a wrong answer and hence give rise to a bad influence on the reputation of the database provider. Furthermore, this protocol is also flexible, loss-resistant and easily generalized to a large database similar to the previous works.

  16. RadSearch: a RIS/PACS integrated query tool

    NASA Astrophysics Data System (ADS)

    Tsao, Sinchai; Documet, Jorge; Moin, Paymann; Wang, Kevin; Liu, Brent J.

    2008-03-01

    Radiology Information Systems (RIS) contain a wealth of information that can be used for research, education, and practice management. However, the sheer amount of information available makes querying specific data difficult and time consuming. Previous work has shown that a clinical RIS database and its RIS text reports can be extracted, duplicated and indexed for searches while complying with HIPAA and IRB requirements. This project's intent is to provide a software tool, the RadSearch Toolkit, to allow intelligent indexing and parsing of RIS reports for easy yet powerful searches. In addition, the project aims to seamlessly query and retrieve associated images from the Picture Archiving and Communication System (PACS) in situations where an integrated RIS/PACS is in place - even subselecting individual series, such as in an MRI study. RadSearch's application of simple text parsing techniques to index text-based radiology reports will allow the search engine to quickly return relevant results. This powerful combination will be useful in both private practice and academic settings; administrators can easily obtain complex practice management information such as referral patterns; researchers can conduct retrospective studies with specific, multiple criteria; teaching institutions can quickly and effectively create thorough teaching files.

  17. A Microprocessor Architecture for Bibliographic Retrieval System.

    ERIC Educational Resources Information Center

    Martella, G.; Gobbi, G.

    1981-01-01

    Proposes a microprocessor-based architecture that makes large use of parallelism both in processing and in retrieval operations. The proposed system consists of three functional blocks: the query processor, simple query executers, and the answer composer. Twenty-one references are listed. (FM)

  18. Interpolation of the Extended Boolean Retrieval Model.

    ERIC Educational Resources Information Center

    Zanger, Daniel Z.

    2002-01-01

    Presents an interpolation theorem for an extended Boolean information retrieval model. Results show that whenever two or more documents are similarly ranked at any two points for a query containing exactly two terms, then they are similarly ranked at all points in between; and that results can fail for queries with more than two terms. (Author/LRW)

  19. Image query based on color harmony

    NASA Astrophysics Data System (ADS)

    Vasile, Alexandru; Bender, Walter R.

    2001-06-01

    The combination of the increased size of digital image databases and the increased frequency with which non- specialist access these databases is raising the question of the efficacy of visual search and retrieval tools. We hypothesize that the use of color harmony has the potential for improving image-search efficiency. We describe an image- retrieval algorithm that relies on a color harmony model. This mode, built on Munsell hue, value, and chroma contrast, is used to divide the image database into clusters that can be individually searched. To test the efficacy of the algorithm, it is compared to existing algorithms developed by Niblack et al and Feldman et al. A second study that utilizes the image query system in a retail application is also described.

  20. An Expressive and Efficient Language for XML Information Retrieval.

    ERIC Educational Resources Information Center

    Chinenyanga, Taurai Tapiwa; Kushmerick, Nicholas

    2002-01-01

    Discusses XML and information retrieval and describes a query language, ELIXIR (expressive and efficient language for XML information retrieval), with a textual similarity operator that can be used for similarity joins. Explains the algorithm for answering ELIXIR queries to generate intermediate relational data. (Author/LRW)

  1. Integration of User Profiles: Models and Experiments in Information Retrieval.

    ERIC Educational Resources Information Center

    Myaeng, Sung H.; Korfhage, Robert R.

    1990-01-01

    Discussion of the interpretation of user queries in information retrieval highlights theoretical models that utilize user characteristics maintained in the form of a user profile. Various query/profile interaction models are identified, and an experiment is described that tested the relevance of retrieved documents based on various models. (29…

  2. An Expressive and Efficient Language for XML Information Retrieval.

    ERIC Educational Resources Information Center

    Chinenyanga, Taurai Tapiwa; Kushmerick, Nicholas

    2002-01-01

    Discusses XML and information retrieval and describes a query language, ELIXIR (expressive and efficient language for XML information retrieval), with a textual similarity operator that can be used for similarity joins. Explains the algorithm for answering ELIXIR queries to generate intermediate relational data. (Author/LRW)

  3. Semantic-Aware Co-Indexing for Image Retrieval.

    PubMed

    Zhang, Shiliang; Yang, Ming; Wang, Xiaoyu; Lin, Yuanqing; Tian, Qi

    2015-12-01

    In content-based image retrieval, inverted indexes allow fast access to database images and summarize all knowledge about the database. Indexing multiple clues of image contents allows retrieval algorithms search for relevant images from different perspectives, which is appealing to deliver satisfactory user experiences. However, when incorporating diverse image features during online retrieval, it is challenging to ensure retrieval efficiency and scalability. In this paper, for large-scale image retrieval, we propose a semantic-aware co-indexing algorithm to jointly embed two strong cues into the inverted indexes: 1) local invariant features that are robust to delineate low-level image contents, and 2) semantic attributes from large-scale object recognition that may reveal image semantic meanings. Specifically, for an initial set of inverted indexes of local features, we utilize semantic attributes to filter out isolated images and insert semantically similar images to this initial set. Encoding these two distinct and complementary cues together effectively enhances the discriminative capability of inverted indexes. Such co-indexing operations are totally off-line and introduce small computation overhead to online retrieval, because only local features but no semantic attributes are employed for the query. Hence, this co-indexing is different from existing image retrieval methods fusing multiple features or retrieval results. Extensive experiments and comparisons with recent retrieval methods manifest the competitive performance of our method.

  4. Optimizing Phylogenetic Queries for Performance.

    PubMed

    Jamil, Hasan M

    2017-08-24

    The vast majority of phylogenetic databases do not support declarative querying using which their contents can be flexibly and conveniently accessed and the template based query interfaces they support do not allow arbitrary speculative queries. They therefore also do not support query optimization leveraging unique phylogeny properties. While a small number of graph query languages such as XQuery, Cypher and GraphQL exist for computer savvy users, most are too general and complex to be useful for biologists, and too inefficient for large phylogeny querying. In this paper, we discuss a recently introduced visual query language, called PhyQL, that leverages phylogeny specific properties to support essential and powerful constructs for a large class of phylogentic queries. We develop a range of pruning aids, and propose a substantial set of query optimization strategies using these aids suitable for large phylogeny querying. A hybrid optimization technique that exploits a set of indices and ``graphlet" partitioning is discussed. A ``fail soonest" strategy is used to avoid hopeless processing and is shown to produce dividends. Possible novel optimization techniques yet to be explored are also discussed.

  5. An effective model for store and retrieve big health data in cloud computing.

    PubMed

    Goli-Malekabadi, Zohreh; Sargolzaei-Javan, Morteza; Akbari, Mohammad Kazem

    2016-08-01

    The volume of healthcare data including different and variable text types, sounds, and images is increasing day to day. Therefore, the storage and processing of these data is a necessary and challenging issue. Generally, relational databases are used for storing health data which are not able to handle the massive and diverse nature of them. This study aimed at presenting the model based on NoSQL databases for the storage of healthcare data. Despite different types of NoSQL databases, document-based DBs were selected by a survey on the nature of health data. The presented model was implemented in the Cloud environment for accessing to the distribution properties. Then, the data were distributed on the database by applying the Shard property. The efficiency of the model was evaluated in comparison with the previous data model, Relational Database, considering query time, data preparation, flexibility, and extensibility parameters. The results showed that the presented model approximately performed the same as SQL Server for "read" query while it acted more efficiently than SQL Server for "write" query. Also, the performance of the presented model was better than SQL Server in the case of flexibility, data preparation and extensibility. Based on these observations, the proposed model was more effective than Relational Databases for handling health data. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Document image retrieval through word shape coding.

    PubMed

    Lu, Shijian; Li, Linlin; Tan, Chew Lim

    2008-11-01

    This paper presents a document retrieval technique that is capable of searching document images without OCR (optical character recognition). The proposed technique retrieves document images by a new word shape coding scheme, which captures the document content through annotating each word image by a word shape code. In particular, we annotate word images by using a set of topological shape features including character ascenders/descenders, character holes, and character water reservoirs. With the annotated word shape codes, document images can be retrieved by either query keywords or a query document image. Experimental results show that the proposed document image retrieval technique is fast, efficient, and tolerant to various types of document degradation.

  7. Effect of Thin Cirrus Clouds on Dust Optical Depth Retrievals From MODIS Observations

    NASA Technical Reports Server (NTRS)

    Feng, Qian; Hsu, N. Christina; Yang, Ping; Tsay, Si-Chee

    2011-01-01

    The effect of thin cirrus clouds in retrieving the dust optical depth from MODIS observations is investigated by using a simplified aerosol retrieval algorithm based on the principles of the Deep Blue aerosol property retrieval method. Specifically, the errors of the retrieved dust optical depth due to thin cirrus contamination are quantified through the comparison of two retrievals by assuming dust-only atmospheres and the counterparts with overlapping mineral dust and thin cirrus clouds. To account for the effect of the polarization state of radiation field on radiance simulation, a vector radiative transfer model is used to generate the lookup tables. In the forward radiative transfer simulations involved in generating the lookup tables, the Rayleigh scattering by atmospheric gaseous molecules and the reflection of the surface assumed to be Lambertian are fully taken into account. Additionally, the spheroid model is utilized to account for the nonsphericity of dust particles In computing their optical properties. For simplicity, the single-scattering albedo, scattering phase matrix, and optical depth are specified a priori for thin cirrus clouds assumed to consist of droxtal ice crystals. The present results indicate that the errors in the retrieved dust optical depths due to the contamination of thin cirrus clouds depend on the scattering angle, underlying surface reflectance, and dust optical depth. Under heavy dusty conditions, the absolute errors are comparable to the predescribed optical depths of thin cirrus clouds.

  8. Effect of Thin Cirrus Clouds on Dust Optical Depth Retrievals From MODIS Observations

    NASA Technical Reports Server (NTRS)

    Feng, Qian; Hsu, N. Christina; Yang, Ping; Tsay, Si-Chee

    2011-01-01

    The effect of thin cirrus clouds in retrieving the dust optical depth from MODIS observations is investigated by using a simplified aerosol retrieval algorithm based on the principles of the Deep Blue aerosol property retrieval method. Specifically, the errors of the retrieved dust optical depth due to thin cirrus contamination are quantified through the comparison of two retrievals by assuming dust-only atmospheres and the counterparts with overlapping mineral dust and thin cirrus clouds. To account for the effect of the polarization state of radiation field on radiance simulation, a vector radiative transfer model is used to generate the lookup tables. In the forward radiative transfer simulations involved in generating the lookup tables, the Rayleigh scattering by atmospheric gaseous molecules and the reflection of the surface assumed to be Lambertian are fully taken into account. Additionally, the spheroid model is utilized to account for the nonsphericity of dust particles In computing their optical properties. For simplicity, the single-scattering albedo, scattering phase matrix, and optical depth are specified a priori for thin cirrus clouds assumed to consist of droxtal ice crystals. The present results indicate that the errors in the retrieved dust optical depths due to the contamination of thin cirrus clouds depend on the scattering angle, underlying surface reflectance, and dust optical depth. Under heavy dusty conditions, the absolute errors are comparable to the predescribed optical depths of thin cirrus clouds.

  9. Content-based retrieval of historical Ottoman documents stored as textual images.

    PubMed

    Saykol, Ediz; Sinop, Ali Kemal; Güdükbay, Ugur; Ulusoy, Ozgür; Cetin, A Enis

    2004-03-01

    There is an accelerating demand to access the visual content of documents stored in historical and cultural archives. Availability of electronic imaging tools and effective image processing techniques makes it feasible to process the multimedia data in large databases. In this paper, a framework for content-based retrieval of historical documents in the Ottoman Empire archives is presented. The documents are stored as textual images, which are compressed by constructing a library of symbols occurring in a document, and the symbols in the original image are then replaced with pointers into the codebook to obtain a compressed representation of the image. The features in wavelet and spatial domain based on angular and distance span of shapes are used to extract the symbols. In order to make content-based retrieval in historical archives, a query is specified as a rectangular region in an input image and the same symbol-extraction process is applied to the query region. The queries are processed on the codebook of documents and the query images are identified in the resulting documents using the pointers in textual images. The querying process does not require decompression of images. The new content-based retrieval framework is also applicable to many other document archives using different scripts.

  10. Content-based histopathological image retrieval for whole slide image database using binary codes

    NASA Astrophysics Data System (ADS)

    Zheng, Yushan; Jiang, Zhiguo; Ma, Yibing; Zhang, Haopeng; Xie, Fengying; Shi, Huaqiang; Zhao, Yu

    2017-03-01

    Content-based image retrieval (CBIR) has been widely researched for medical images. In application of histo- pathological images, there are two issues that need to be carefully considered. The one is that the digital slide is stored in a spatially continuous image with a size of more than 10K x 10K pixels. The other is that the size of query image varies in a large range according to different diagnostic conditions. It is a challenging work to retrieve the eligible regions for the query image from the database that consists of whole slide images (WSIs). In this paper, we proposed a CBIR framework for the WSI database and size-scalable query images. Each WSI in the database is encoded and stored in a matrix of binary codes. When retrieving, the query image is first encoded into a set of binary codes and analyzed to pre-choose a set of regions from database using hashing method. Then a multi-binary-code-based similarity measurement based on hamming distance is designed to rank proposal regions. Finally, the top relevant regions and their locations in the WSIs along with the diagnostic information are returned to assist pathologists in diagnoses. The effectiveness of the proposed framework is evaluated in a fine-annotated WSIs database of epithelial breast tumors. The experimental results show that proposed framework is both effective and efficiency for content-based whole slide image retrieval.

  11. Exploring the Effects of Cloud Vertical Structure on Cloud Microphysical Retrievals based on Polarized Reflectances

    NASA Astrophysics Data System (ADS)

    Miller, D. J.; Zhang, Z.; Platnick, S. E.; Ackerman, A. S.; Cornet, C.; Baum, B. A.

    2013-12-01

    A polarized cloud reflectance simulator was developed by coupling an LES cloud model with a polarized radiative transfer model to assess the capabilities of polarimetric cloud retrievals. With future remote sensing campaigns like NASA's Aerosols/Clouds/Ecosystems (ACE) planning to feature advanced polarimetric instruments it is important for the cloud remote sensing community to understand the retrievable information available and the related systematic/methodical limitations. The cloud retrieval simulator we have developed allows us to probe these important questions in a realistically relevant test bed. Our simulator utilizes a polarized adding-doubling radiative transfer model and an LES cloud field from a DHARMA simulation (Ackerman et al. 2004) with cloud properties based on the stratocumulus clouds observed during the DYCOMS-II field campaign. In this study we will focus on how the vertical structure of cloud microphysics can influence polarized cloud effective radius retrievals. Numerous previous studies have explored how retrievals based on total reflectance are affected by cloud vertical structure (Platnick 2000, Chang and Li 2002) but no such studies about the effects of vertical structure on polarized retrievals exist. Unlike the total cloud reflectance, which is predominantly multiply scattered light, the polarized reflectance is primarily the result of singly scattered photons. Thus the polarized reflectance is sensitive to only the uppermost region of the cloud (tau~<1) where photons can scatter once and still escape before being scattered again. This means that retrievals based on polarized reflectance have the potential to reveal behaviors specific to the cloud top. For example cloud top entrainment of dry air, a major influencer on the microphysical development of cloud droplets, can be potentially studied with polarimetric retrievals.

  12. Optical Thickness and Effective Radius Retrievals of Liquid Water Clouds over Ice and Snow Surface

    NASA Technical Reports Server (NTRS)

    Platnick, S.; King, M. D.; Tsay, S.-C.; Arnold, G. T.; Gerber, H.; Hobbs, P. V.; Rangno, A.

    1999-01-01

    Cloud optical thickness and effective radius retrievals from solar reflectance measurements traditionally depend on a combination of spectral channels that are absorbing and non-absorbing for liquid water droplets. Reflectances in non-absorbing channels (e.g., 0.67, 0.86 micrometer bands) are largely dependent on cloud optical thickness, while longer wavelength absorbing channels (1.6, 2.1, and 3.7 micrometer window bands) provide cloud particle size information. Retrievals are complicated by the presence of an underlying ice/snow surface. At the shorter wavelengths, sea ice is both bright and highly variable, significantly increasing cloud retrieval uncertainty. However, reflectances at the longer wavelengths are relatively small and may be comparable to that of dark open water. Sea ice spectral albedos derived from Cloud Absorption Radiometer (CAR) measurements during April 1992 and June 1995 Arctic field deployments are used to illustrate these statements. A modification to the traditional retrieval technique is devised. The new algorithm uses a combination of absorbing spectral channels for which the snow/ice albedo is relatively small. Using this approach, preliminary retrievals have been made with the MODIS Airborne Simulator (MAS) imager flown aboard the NASA ER-2 during FIRE-ACE. Data from coordinated ER-2 and University of Washington CV-580 aircraft observations of liquid water stratus clouds on June 3 and June 6, 1998 have been examined. Size retrievals are compared with in situ cloud profile measurements of effective radius made with the CV-580 PMS FSSP probe, and optical thickness retrievals are compared with extinction profiles derived from the Gerber Scientific "g-meter" probe. MAS retrievals are shown to be in good agreement with the in situ measurements.

  13. A Graphical Query Language for Querying Petri Nets

    NASA Astrophysics Data System (ADS)

    Xiao, Lan; Zheng, Li; Xiao, Jian; Huang, Yi

    As the number of business process models increases, providing business analysts and IT experts with a query langue for querying business process models is of great practical value. This paper uses Petri net as business process modeling language and develops Petri Net Query Language (PNQL), a graphical query language for Petri nets. The syntax and semantics of PNQL are formally studied. PNQL allows users to get not only the perfectly matched Petri nets but also the Petri nets with high similarity. The complexity of PNQL is studied.

  14. Query-Based Outlier Detection in Heterogeneous Information Networks.

    PubMed

    Kuck, Jonathan; Zhuang, Honglei; Yan, Xifeng; Cam, Hasan; Han, Jiawei

    2015-03-01

    Outlier or anomaly detection in large data sets is a fundamental task in data science, with broad applications. However, in real data sets with high-dimensional space, most outliers are hidden in certain dimensional combinations and are relative to a user's search space and interest. It is often more effective to give power to users and allow them to specify outlier queries flexibly, and the system will then process such mining queries efficiently. In this study, we introduce the concept of query-based outlier in heterogeneous information networks, design a query language to facilitate users to specify such queries flexibly, define a good outlier measure in heterogeneous networks, and study how to process outlier queries efficiently in large data sets. Our experiments on real data sets show that following such a methodology, interesting outliers can be defined and uncovered flexibly and effectively in large heterogeneous networks.

  15. Query-Based Outlier Detection in Heterogeneous Information Networks

    PubMed Central

    Kuck, Jonathan; Zhuang, Honglei; Yan, Xifeng; Cam, Hasan; Han, Jiawei

    2015-01-01

    Outlier or anomaly detection in large data sets is a fundamental task in data science, with broad applications. However, in real data sets with high-dimensional space, most outliers are hidden in certain dimensional combinations and are relative to a user’s search space and interest. It is often more effective to give power to users and allow them to specify outlier queries flexibly, and the system will then process such mining queries efficiently. In this study, we introduce the concept of query-based outlier in heterogeneous information networks, design a query language to facilitate users to specify such queries flexibly, define a good outlier measure in heterogeneous networks, and study how to process outlier queries efficiently in large data sets. Our experiments on real data sets show that following such a methodology, interesting outliers can be defined and uncovered flexibly and effectively in large heterogeneous networks. PMID:27064397

  16. Machine translation-supported cross-language information retrieval for a consumer health resource.

    PubMed

    Rosemblat, Graciela; Gemoets, Darren; Browne, Allen C; Tse, Tony

    2003-01-01

    The U.S. National Institutes of Health, through its National Library of Medicine, developed ClinicalTrials.gov to provide the public with easy access to information on clinical trials on a wide range of conditions or diseases. Only English language information retrieval is currently supported. Given the growing number of Spanish speakers in the U.S. and their increasing use of the Web, we anticipate a significant increase in Spanish-speaking users. This study compares the effectiveness of two common cross-language information retrieval methods using machine translation, query translation versus document translation, using a subset of genuine user queries from ClinicalTrials.gov. Preliminary results conducted with the ClinicalTrials.gov search engine show that in our environment, query translation is statistically significantly better than document translation. We discuss possible reasons for this result and we conclude with suggestions for future work.

  17. Web-based multimedia information retrieval for clinical application research

    NASA Astrophysics Data System (ADS)

    Cao, Xinhua; Hoo, Kent S., Jr.; Zhang, Hong; Ching, Wan; Zhang, Ming; Wong, Stephen T. C.

    2001-08-01

    We described a web-based data warehousing method for retrieving and analyzing neurological multimedia information. The web-based method supports convenient access, effective search and retrieval of clinical textual and image data, and on-line analysis. To improve the flexibility and efficiency of multimedia information query and analysis, a three-tier, multimedia data warehouse for epilepsy research has been built. The data warehouse integrates clinical multimedia data related to epilepsy from disparate sources and archives them into a well-defined data model.

  18. The effect of row structure on soil moisture retrieval accuracy from passive microwave data.

    PubMed

    Xingming, Zheng; Kai, Zhao; Yangyang, Li; Jianhua, Ren; Yanling, Ding

    2014-01-01

    Row structure causes the anisotropy of microwave brightness temperature (TB) of soil surface, and it also can affect soil moisture retrieval accuracy when its influence is ignored in the inversion model. To study the effect of typical row structure on the retrieved soil moisture and evaluate if there is a need to introduce this effect into the inversion model, two ground-based experiments were carried out in 2011. Based on the observed C-band TB, field soil and vegetation parameters, row structure rough surface assumption (Q p model and discrete model), including the effect of row structure, and flat rough surface assumption (Q p model), ignoring the effect of row structure, are used to model microwave TB of soil surface. Then, soil moisture can be retrieved, respectively, by minimizing the difference of the measured and modeled TB. The results show that soil moisture retrieval accuracy based on the row structure rough surface assumption is approximately 0.02 cm(3)/cm(3) better than the flat rough surface assumption for vegetated soil, as well as 0.015 cm(3)/cm(3) better for bare and wet soil. This result indicates that the effect of row structure cannot be ignored for accurately retrieving soil moisture of farmland surface when C-band is used.

  19. The Effect of Row Structure on Soil Moisture Retrieval Accuracy from Passive Microwave Data

    PubMed Central

    Xingming, Zheng; Kai, Zhao; Yangyang, Li; Jianhua, Ren; Yanling, Ding

    2014-01-01

    Row structure causes the anisotropy of microwave brightness temperature (TB) of soil surface, and it also can affect soil moisture retrieval accuracy when its influence is ignored in the inversion model. To study the effect of typical row structure on the retrieved soil moisture and evaluate if there is a need to introduce this effect into the inversion model, two ground-based experiments were carried out in 2011. Based on the observed C-band TB, field soil and vegetation parameters, row structure rough surface assumption (Qp model and discrete model), including the effect of row structure, and flat rough surface assumption (Qp model), ignoring the effect of row structure, are used to model microwave TB of soil surface. Then, soil moisture can be retrieved, respectively, by minimizing the difference of the measured and modeled TB. The results show that soil moisture retrieval accuracy based on the row structure rough surface assumption is approximately 0.02 cm3/cm3 better than the flat rough surface assumption for vegetated soil, as well as 0.015 cm3/cm3 better for bare and wet soil. This result indicates that the effect of row structure cannot be ignored for accurately retrieving soil moisture of farmland surface when C-band is used. PMID:25386626

  20. Study of the geometry effect on land surface temperature retrieval in urban environment

    NASA Astrophysics Data System (ADS)

    Yang, Jinxin; Wong, Man Sing; Menenti, Massimo; Nichol, Janet

    2015-11-01

    This study presents a Single Channel Method using Urban Exitance Model (UEM-SCM) to retrieve land surface temperature (LST) from satellite data in an urbanized city, and evaluates the geometry effect on land surface temperature retrieval using single channel method and split-window algorithm. The UEM-SCM incorporates the effect of urban geometry and considers both reflection caused by the target pixel and its neighboring pixels. In order to evaluate the geometry effect, the retrieved LSTs with and without geometry effect were studied. Results show that the LSTs without geometry effect are generally higher than the LSTs with geometry effect. The temperature difference occurs because the material emissivity is always lower than the effective emissivity caused by multiple scattering and reflection in urban areas (cavity effect). The LST without geometry effect also cannot fully capture the variability and complexity of urban thermal patterns. The temperature difference between with and without the geometry effect can reach 2 K in built-up areas. A comparison was also conducted between LST retrieved by split-window algorithm with and without geometry effect. Results show that the LST retrieved by split-window algorithm without geometry effect has generally higher values than the one with the geometry effect, e.g. 1.1 K on average and 1.5-2 K in built-up areas. The geometry effect will be removed and mis-deemed as atmospheric effect when the split-window algorithm without geometry effect is applied in urban areas. The split-window algorithm with the geometry effect can be used to distinguish between geometry and atmospheric effect in further study.

  1. Smart Query Answering for Marine Sensor Data

    PubMed Central

    Shahriar, Md. Sumon; de Souza, Paulo; Timms, Greg

    2011-01-01

    We review existing query answering systems for sensor data. We then propose an extended query answering approach termed smart query, specifically for marine sensor data. The smart query answering system integrates pattern queries and continuous queries. The proposed smart query system considers both streaming data and historical data from marine sensor networks. The smart query also uses query relaxation technique and semantics from domain knowledge as a recommender system. The proposed smart query benefits in building data and information systems for marine sensor networks. PMID:22163772

  2. The CMS DBS query language

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Valentin; Riley, Daniel; Afaq, Anzar; Sekhri, Vijay; Guo, Yuyi; Lueking, Lee

    2010-04-01

    The CMS experiment has implemented a flexible and powerful system enabling users to find data within the CMS physics data catalog. The Dataset Bookkeeping Service (DBS) comprises a database and the services used to store and access metadata related to CMS physics data. To this, we have added a generalized query system in addition to the existing web and programmatic interfaces to the DBS. This query system is based on a query language that hides the complexity of the underlying database structure by discovering the join conditions between database tables. This provides a way of querying the system that is simple and straightforward for CMS data managers and physicists to use without requiring knowledge of the database tables or keys. The DBS Query Language uses the ANTLR tool to build the input query parser and tokenizer, followed by a query builder that uses a graph representation of the DBS schema to construct the SQL query sent to underlying database. We will describe the design of the query system, provide details of the language components and overview of how this component fits into the overall data discovery system architecture.

  3. VISAGE: Interactive Visual Graph Querying.

    PubMed

    Pienta, Robert; Navathe, Shamkant; Tamersoy, Acar; Tong, Hanghang; Endert, Alex; Chau, Duen Horng

    2016-06-01

    Extracting useful patterns from large network datasets has become a fundamental challenge in many domains. We present VISAGE, an interactive visual graph querying approach that empowers users to construct expressive queries, without writing complex code (e.g., finding money laundering rings of bankers and business owners). Our contributions are as follows: (1) we introduce graph autocomplete, an interactive approach that guides users to construct and refine queries, preventing over-specification; (2) VISAGE guides the construction of graph queries using a data-driven approach, enabling users to specify queries with varying levels of specificity, from concrete and detailed (e.g., query by example), to abstract (e.g., with "wildcard" nodes of any types), to purely structural matching; (3) a twelve-participant, within-subject user study demonstrates VISAGE's ease of use and the ability to construct graph queries significantly faster than using a conventional query language; (4) VISAGE works on real graphs with over 468K edges, achieving sub-second response times for common queries.

  4. VISAGE: Interactive Visual Graph Querying

    PubMed Central

    Pienta, Robert; Navathe, Shamkant; Tamersoy, Acar; Tong, Hanghang; Endert, Alex; Chau, Duen Horng

    2017-01-01

    Extracting useful patterns from large network datasets has become a fundamental challenge in many domains. We present VISAGE, an interactive visual graph querying approach that empowers users to construct expressive queries, without writing complex code (e.g., finding money laundering rings of bankers and business owners). Our contributions are as follows: (1) we introduce graph autocomplete, an interactive approach that guides users to construct and refine queries, preventing over-specification; (2) VISAGE guides the construction of graph queries using a data-driven approach, enabling users to specify queries with varying levels of specificity, from concrete and detailed (e.g., query by example), to abstract (e.g., with “wildcard” nodes of any types), to purely structural matching; (3) a twelve-participant, within-subject user study demonstrates VISAGE’s ease of use and the ability to construct graph queries significantly faster than using a conventional query language; (4) VISAGE works on real graphs with over 468K edges, achieving sub-second response times for common queries. PMID:28553670

  5. Passage Retrieval and Evaluation

    DTIC Science & Technology

    2005-02-01

    queries, is IDF(t) = log „ # docs. in corpus + 1 0.5 + # docs. t appears in « . (6) This rather ad hoc scoring formula is implemented in the Lemur ...problems with passage R-precision as an evaluation metric. Fernando was instrumental in extending the Lemur toolkit to make all of these experiments...and C. Zhai. The lemur toolkit for language modeling and information retrieval. http://www.cs.cmu.edu/∼ lemur /, 2003. [6] C. Buckley and E. M

  6. The effect of ketorolac on pregnancy rates when used immediately after oocyte retrieval.

    PubMed

    Mesen, Tolga B; Kacemi-Bourhim, Lamya; Marshburn, Paul B; Usadi, Rebecca S; Matthews, Michelle; Norton, H James; Hurst, Bradley S

    2013-09-01

    To study the effect of ketorolac, a potent anti-inflammatory medication, on in vitro fertilization (IVF) pregnancy outcomes when used at the time of oocyte retrieval. Retrospective review of 454 patients from 2003-2009. Tertiary hospital-affiliated fertility center. Consecutive subfertile women undergoing their first IVF cycle. Ketorolac administration immediately after oocyte retrieval. Pregnancy, implantation, live-birth, and miscarriage rates, and postsurgical visual analog pain score. Of the 454 patients undergoing their first IVF cycle for all indications, 103 received intravenous ketorolac immediately after oocyte retrieval, based on anesthesiologist preference. Patient and procedural characteristics were similar between both groups. The use of ketorolac had no effect on the rates of implantation, miscarriage, pregnancy, live birth, or multiple pregnancy. The patients receiving ketorolac experienced statistically significantly less pain. This study suggests ketorolac has no apparent detrimental effect on IVF pregnancy outcomes when administered immediately after oocyte retrieval. Ketorolac appears to be a safe and effective analgesic to use at the time of oocyte retrieval. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  7. Improve Biomedical Information Retrieval using Modified Learning to Rank Methods.

    PubMed

    Xu, Bo; Lin, Hongfei; Lin, Yuan; Ma, Yunlong; Yang, Liang; Wang, Jian; Yang, Zhihao

    2016-06-14

    In these years, the number of biomedical articles has increased exponentially, which becomes a problem for biologists to capture all the needed information manually. Information retrieval technologies, as the core of search engines, can deal with the problem automatically, providing users with the needed information. However, it is a great challenge to apply these technologies directly for biomedical retrieval, because of the abundance of domain specific terminologies. To enhance biomedical retrieval, we propose a novel framework based on learning to rank. Learning to rank is a series of state-of-the-art information retrieval techniques, and has been proved effective in many information retrieval tasks. In the proposed framework, we attempt to tackle the problem of the abundance of terminologies by constructing ranking models, which focus on not only retrieving the most relevant documents, but also diversifying the searching results to increase the completeness of the resulting list for a given query. In the model training, we propose two novel document labeling strategies, and combine several traditional retrieval models as learning features. Besides, we also investigate the usefulness of different learning to rank approaches in our framework. Experimental results on TREC Genomics datasets demonstrate the effectiveness of our framework for biomedical information retrieval.

  8. Matching health information seekers' queries to medical terms

    PubMed Central

    2012-01-01

    Background The Internet is a major source of health information but most seekers are not familiar with medical vocabularies. Hence, their searches fail due to bad query formulation. Several methods have been proposed to improve information retrieval: query expansion, syntactic and semantic techniques or knowledge-based methods. However, it would be useful to clean those queries which are misspelled. In this paper, we propose a simple yet efficient method in order to correct misspellings of queries submitted by health information seekers to a medical online search tool. Methods In addition to query normalizations and exact phonetic term matching, we tested two approximate string comparators: the similarity score function of Stoilos and the normalized Levenshtein edit distance. We propose here to combine them to increase the number of matched medical terms in French. We first took a sample of query logs to determine the thresholds and processing times. In the second run, at a greater scale we tested different combinations of query normalizations before or after misspelling correction with the retained thresholds in the first run. Results According to the total number of suggestions (around 163, the number of the first sample of queries), at a threshold comparator score of 0.3, the normalized Levenshtein edit distance gave the highest F-Measure (88.15%) and at a threshold comparator score of 0.7, the Stoilos function gave the highest F-Measure (84.31%). By combining Levenshtein and Stoilos, the highest F-Measure (80.28%) is obtained with 0.2 and 0.7 thresholds respectively. However, queries are composed by several terms that may be combination of medical terms. The process of query normalization and segmentation is thus required. The highest F-Measure (64.18%) is obtained when this process is realized before spelling-correction. Conclusions Despite the widely known high performance of the normalized edit distance of Levenshtein, we show in this paper that its

  9. The effect of retrieval on recall of information in individuals with posttraumatic stress disorder.

    PubMed

    Amir, Nader; Badour, Christal L; Freese, Bettina

    2009-05-01

    Cognitive theories of posttraumatic stress disorder (PTSD) suggest that associative memory processes may play a crucial role in the development and maintenance of the disorder. In the current study we examined the effect of associative pair rehearsal on recall ability for threatening and non-threatening information using the retrieval-practice paradigm in individuals with PTSD, traumatized controls (TC), and non-traumatized controls (NAC). Across word type, NACs demonstrated a typical retrieval-induced forgetting effect. However, individuals with PTSD benefited less from rehearsal, and failed to inhibit recall of unpracticed words in practiced categories. Participants in the TC group displayed a retrieval-induced forgetting effect similar to those individuals in the PTSD group. These findings are consistent with research indicating that individuals with PTSD may derive less benefit from rehearsal and display general inhibitory difficulties when compared to non-traumatized controls.

  10. The effect of retrieval on recall of information in individuals with posttraumatic stress disorder☆

    PubMed Central

    Amir, Nader; Badour, Christal L.; Freese, Bettina

    2013-01-01

    Cognitive theories of posttraumatic stress disorder (PTSD) suggest that associative memory processes may play a crucial role in the development and maintenance of the disorder. In the current study we examined the effect of associative pair rehearsal on recall ability for threatening and non-threatening information using the retrieval-practice paradigm in individuals with PTSD, traumatized controls (TC), and non-traumatized controls (NAC). Across word type, NACs demonstrated a typical retrieval-induced forgetting effect. However, individuals with PTSD benefited less from rehearsal, and failed to inhibit recall of unpracticed words in practiced categories. Participants in the TC group displayed a retrieval-induced forgetting effect similar to those individuals in the PTSD group. These findings are consistent with research indicating that individuals with PTSD may derive less benefit from rehearsal and display general inhibitory difficulties when compared to non-traumatized controls. PMID:19070459

  11. VPipe: Virtual Pipelining for Scheduling of DAG Stream Query Plans

    NASA Astrophysics Data System (ADS)

    Wang, Song; Gupta, Chetan; Mehta, Abhay

    There are data streams all around us that can be harnessed for tremendous business and personal advantage. For an enterprise-level stream processing system such as CHAOS [1] (Continuous, Heterogeneous Analytic Over Streams), handling of complex query plans with resource constraints is challenging. While several scheduling strategies exist for stream processing, efficient scheduling of complex DAG query plans is still largely unsolved. In this paper, we propose a novel execution scheme for scheduling complex directed acyclic graph (DAG) query plans with meta-data enriched stream tuples. Our solution, called Virtual Pipelined Chain (or VPipe Chain for short), effectively extends the "Chain" pipelining scheduling approach to complex DAG query plans.

  12. Automatic Building Information Model Query Generation

    SciTech Connect

    Jiang, Yufei; Yu, Nan; Ming, Jiang; Lee, Sanghoon; DeGraw, Jason; Yen, John; Messner, John I.; Wu, Dinghao

    2015-12-01

    Energy efficient building design and construction calls for extensive collaboration between different subfields of the Architecture, Engineering and Construction (AEC) community. Performing building design and construction engineering raises challenges on data integration and software interoperability. Using Building Information Modeling (BIM) data hub to host and integrate building models is a promising solution to address those challenges, which can ease building design information management. However, the partial model query mechanism of current BIM data hub collaboration model has several limitations, which prevents designers and engineers to take advantage of BIM. To address this problem, we propose a general and effective approach to generate query code based on a Model View Definition (MVD). This approach is demonstrated through a software prototype called QueryGenerator. By demonstrating a case study using multi-zone air flow analysis, we show how our approach and tool can help domain experts to use BIM to drive building design with less labour and lower overhead cost.

  13. Automatic building information model query generation

    SciTech Connect

    Jiang, Yufei; Yu, Nan; Ming, Jiang; Lee, Sanghoon; DeGraw, Jason; Yen, John; Messner, John I.; Wu, Dinghao

    2015-12-01

    Energy efficient building design and construction calls for extensive collaboration between different subfields of the Architecture, Engineering and Construction (AEC) community. Performing building design and construction engineering raises challenges on data integration and software interoperability. Using Building Information Modeling (BIM) data hub to host and integrate building models is a promising solution to address those challenges, which can ease building design information management. However, the partial model query mechanism of current BIM data hub collaboration model has several limitations, which prevents designers and engineers to take advantage of BIM. To address this problem, we propose a general and effective approach to generate query code based on a Model View Definition (MVD). This approach is demonstrated through a software prototype called QueryGenerator. In conclusion, by demonstrating a case study using multi-zone air flow analysis, we show how our approach and tool can help domain experts to use BIM to drive building design with less labour and lower overhead cost.

  14. Glucocorticoid effects on memory retrieval require concurrent noradrenergic activity in the hippocampus and basolateral amygdala.

    PubMed

    Roozendaal, Benno; Hahn, Emily L; Nathan, Sheila V; de Quervain, Dominique J-F; McGaugh, James L

    2004-09-15

    Previous findings indicate that administration of abeta-adrenoceptor antagonist systemically blocks glucocorticoid impairment of memory retrieval. Here, we report that beta-adrenoceptor activation in the hippocampus and the basolateral complex of the amygdala (BLA) is implicated in the impairing effects of glucocorticoids on memory retrieval. The specific glucocorticoid receptor (GR) agonist 11beta,17beta-dihydroxy-6,21-dimethyl-17alpha-pregna-4,6-trien-20yn-3-one (RU 28362) (15 ng) infused into the hippocampus of male Sprague Dawley rats 60 min before water maze retention testing, 24 hr after training, impaired probe trial retention performance, as assessed by quadrant search time and initial latency to cross the platform location. Because we found previously that RU 28362 infused into the hippocampus does not affect water maze acquisition or immediate recall, the findings suggest that the GR agonist-induced retention impairment was attributable to a selective influence on long-term memory retrieval. Likewise, systemic injections of the beta1-adrenoceptor partial agonist xamoterol (3.0 or 10.0 mg/kg, s.c.) 60 min before the probe trial dose-dependently impaired retention performance. The beta-adrenoceptor antagonist propranolol (2.0 mg/kg) administered subcutaneously before retention testing did not affect retention performance alone, but blocked the memory retrieval impairment induced by concurrent intrahippocampal infusions of RU 28362. Pretest infusions of the beta1-adrenoceptor antagonist atenolol into either the hippocampus (1.25 microg in 0.5 microl) or the BLA (0.5 microg in 0.2 microl) also prevented the GR agonist-induced memory retrieval impairment. These findings suggest that glucocorticoids impair retrieval of long-term spatial memory by facilitating noradrenergic mechanisms in the hippocampus, and additionally, that norepinephrine-mediated BLA activity is critical in enabling hippocampal glucocorticoid effects on memory retrieval.

  15. The Effect of Retrieval on Post-Task Enjoyment of Studying

    ERIC Educational Resources Information Center

    Clark, Daniel A.; Svinicki, Marilla

    2015-01-01

    Although active retrieval is an extremely effective study method, students continue to use less effective methods (Karpicke, "Journal of Experimental Psychology General," 138(4), 469-486, 2009; Hartwig and Dunlosky, "Psychonomic Bulletin & Review," 19(1), 126-134, 2012). There are likely many underlying reasons for using…

  16. The Effect of Retrieval on Post-Task Enjoyment of Studying

    ERIC Educational Resources Information Center

    Clark, Daniel A.; Svinicki, Marilla

    2015-01-01

    Although active retrieval is an extremely effective study method, students continue to use less effective methods (Karpicke, "Journal of Experimental Psychology General," 138(4), 469-486, 2009; Hartwig and Dunlosky, "Psychonomic Bulletin & Review," 19(1), 126-134, 2012). There are likely many underlying reasons for using…

  17. Effect of stratospheric aerosol layers on the TOMS/SBUV ozone retrieval

    NASA Technical Reports Server (NTRS)

    Torres, O.; Ahmad, Zia; Pan, L.; Herman, J. R.; Bhartia, P. K.; Mcpeters, R.

    1994-01-01

    An evaluation of the optical effects of stratospheric aerosol layers on total ozone retrieval from space by the TOMS/SBUV type instruments is presented here. Using the Dave radiative transfer model we estimate the magnitude of the errors in the retrieved ozone when polar stratospheric clouds (PSC's) or volcanic aerosol layers interfere with the measurements. The largest errors are produced by optically thick water ice PSC's. Results of simulation experiments on the effect of the Pinatubo aerosol cloud on the Nimbus-7 and Meteor-3 TOMS products are presented.

  18. Estimate of the Impact of Absorbing Aerosol Over Cloud on the MODIS Retrievals of Cloud Optical Thickness and Effective Radius Using Two Independent Retrievals of Liquid Water Path

    NASA Technical Reports Server (NTRS)

    Wilcox, Eric M.; Harshvardhan; Platnick, Steven

    2009-01-01

    Two independent satellite retrievals of cloud liquid water path (LWP) from the NASA Aqua satellite are used to diagnose the impact of absorbing biomass burning aerosol overlaying boundary-layer marine water clouds on the Moderate Resolution Imaging Spectrometer (MODIS) retrievals of cloud optical thickness (tau) and cloud droplet effective radius (r(sub e)). In the MODIS retrieval over oceans, cloud reflectance in the 0.86-micrometer and 2.13-micrometer bands is used to simultaneously retrieve tau and r(sub e). A low bias in the MODIS tau retrieval may result from reductions in the 0.86-micrometer reflectance, which is only very weakly absorbed by clouds, owing to absorption by aerosols in cases where biomass burning aerosols occur above water clouds. MODIS LWP, derived from the product of the retrieved tau and r(sub e), is compared with LWP ocean retrievals from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E), determined from cloud microwave emission that is transparent to aerosols. For the coastal Atlantic southern African region investigated in this study, a systematic difference between AMSR-E and MODIS LWP retrievals is found for stratocumulus clouds over three biomass burning months in 2005 and 2006 that is consistent with above-cloud absorbing aerosols. Biomass burning aerosol is detected using the ultraviolet aerosol index from the Ozone Monitoring Instrument (OMI) on the Aura satellite. The LWP difference (AMSR-E minus MODIS) increases both with increasing tau and increasing OMI aerosol index. During the biomass burning season the mean LWP difference is 14 g per square meters, which is within the 15-20 g per square meter range of estimated uncertainties in instantaneous LWP retrievals. For samples with only low amounts of overlaying smoke (OMI AI less than or equal to 1) the difference is 9.4, suggesting that the impact of smoke aerosols on the mean MODIS LWP is 5.6 g per square meter. Only for scenes with OMI aerosol index greater than 2 does the

  19. Considering Combined or Separated Roughness and Vegetation Effects in Soil Moisture Retrievals

    NASA Technical Reports Server (NTRS)

    Parrens, Marie; Wigernon, Jean-Pierre; Richaume, Philippe; Al Bitar, Ahmad; Mialon, Arnaud; Fernandez-Moran, Roberto; Al-Yarri, Amen; O'Neill, Peggy; Kerr, Yann

    2016-01-01

    For more than six years, the Soil Moisture and Ocean Salinity (SMOS) mission has provided multi angular and full-polarization brightness temperature (TB) measurements at L-band. Geophysical products such as soil moisture (SM) and vegetation optical depth at nadir (tau(sub nad)) are retrieved by an operational algorithm using TB observations at different angles of incidence and polarizations. However, the quality of the retrievals depends on several surface effects, such as vegetation, soil roughness and texture, etc. In the microwave forward emission model used in the retrievals (L-band Microwave Emission Model, L-MEB),soil roughness is modeled with a semi-empirical equation using four main parameters (Q(sub r), H(sub r), N(sub rp), with p = H or V polarizations). At present, these parameters are calibrated with data provided by airborne studies and in situ measurements made at a local scale that is not necessarily representative of the large SMOS footprints (43 km on average) at global scale. In this study, we evaluate the impact of the calibrated values of N(sub rp) and H(sub r) on the SM and tau(sub nad) retrievals based on SMOS TB measurements (SMOS Level 3 product) over the Soil Climate Analysis Network (SCAN) network located in North America over five years (2011-2015). In this study, Qr was set equal to zero and we assumed that N(sub rH)= N(sub rV). The retrievals were performed by varying N(sub rp) from -1 to 2 by steps of 1 and H(sub r) from 0 to 0.6 by steps of 0.1. At satellite scale, the results show that combining vegetation and roughness effects in a single parameter provides the best results in terms of soil moisture retrievals, as evaluated against the in situ SM data. Even though our retrieval approach was very simplified, as we did not account for pixel heterogeneity, the accuracy we obtained in the SM retrievals was almost systematically better than those of the Level 3 product. Improved results were also obtained in terms of optical depth

  20. Considering Combined or Separated Roughness and Vegetation Effects in Soil Moisture Retrievals

    NASA Technical Reports Server (NTRS)

    Parrens, Marie; Wigernon, Jean-Pierre; Richaume, Philippe; Al Bitar, Ahmad; Mialon, Arnaud; Fernandez-Moran, Roberto; Al-Yarri, Amen; O'Neill, Peggy; Kerr, Yann

    2016-01-01

    For more than six years, the Soil Moisture and Ocean Salinity (SMOS) mission has provided multi angular and full-polarization brightness temperature (TB) measurements at L-band. Geophysical products such as soil moisture (SM) and vegetation optical depth at nadir (tau(sub nad)) are retrieved by an operational algorithm using TB observations at different angles of incidence and polarizations. However, the quality of the retrievals depends on several surface effects, such as vegetation, soil roughness and texture, etc. In the microwave forward emission model used in the retrievals (L-band Microwave Emission Model, L-MEB),soil roughness is modeled with a semi-empirical equation using four main parameters (Q(sub r), H(sub r), N(sub rp), with p = H or V polarizations). At present, these parameters are calibrated with data provided by airborne studies and in situ measurements made at a local scale that is not necessarily representative of the large SMOS footprints (43 km on average) at global scale. In this study, we evaluate the impact of the calibrated values of N(sub rp) and H(sub r) on the SM and tau(sub nad) retrievals based on SMOS TB measurements (SMOS Level 3 product) over the Soil Climate Analysis Network (SCAN) network located in North America over five years (2011-2015). In this study, Qr was set equal to zero and we assumed that N(sub rH)= N(sub rV). The retrievals were performed by varying N(sub rp) from -1 to 2 by steps of 1 and H(sub r) from 0 to 0.6 by steps of 0.1. At satellite scale, the results show that combining vegetation and roughness effects in a single parameter provides the best results in terms of soil moisture retrievals, as evaluated against the in situ SM data. Even though our retrieval approach was very simplified, as we did not account for pixel heterogeneity, the accuracy we obtained in the SM retrievals was almost systematically better than those of the Level 3 product. Improved results were also obtained in terms of optical depth

  1. Considering combined or separated roughness and vegetation effects in soil moisture retrievals

    NASA Astrophysics Data System (ADS)

    Parrens, Marie; Wigneron, Jean-Pierre; Richaume, Philippe; Al Bitar, Ahmad; Mialon, Arnaud; Fernandez-Moran, Roberto; Al-Yaari, Amen; O'Neill, Peggy; Kerr, Yann

    2017-03-01

    For more than six years, the Soil Moisture and Ocean Salinity (SMOS) mission has provided multi angular and full-polarization brightness temperature (TB) measurements at L-band. Geophysical products such as soil moisture (SM) and vegetation optical depth at nadir (τnad) are retrieved by an operational algorithm using TB observations at different angles of incidence and polarizations. However, the quality of the retrievals depends on several surface effects, such as vegetation, soil roughness and texture, etc. In the microwave forward emission model used in the retrievals (L-band Microwave Emission Model, L-MEB), soil roughness is modelled with a semi-empirical equation using four main parameters (Qr, Hr, Nrp, with p = H or V polarizations). At present, these parameters are calibrated with data provided by airborne studies and in situ measurements made at a local scale that is not necessarily representative of the large SMOS footprints (43 km on average) at global scale. In this study, we evaluate the impact of the calibrated values of Nrp and Hr on the SM and τnad retrievals based on SMOS TB measurements (SMOS Level 3 product) over the Soil Climate Analysis Network (SCAN) network located in North America over five years (2011-2015). In this study, Qr was set equal to zero and we assumed that NrH = NrV. The retrievals were performed by varying Nrp from -1 to 2 by steps of 1 and Hr from 0 to 0.6 by steps of 0.1. At satellite scale, the results show that combining vegetation and roughness effects in a single parameter provides the best results in terms of soil moisture retrievals, as evaluated against the in situ SM data. Even though our retrieval approach was very simplified, as we did not account for pixel heterogeneity, the accuracy we obtained in the SM retrievals was almost systematically better than those of the Level 3 product. Improved results were also obtained in terms of optical depth retrievals. These new results may have key consequences in terms of

  2. Mitigating the effect of noise in the hybrid input-output method of phase retrieval.

    PubMed

    Trahan, Russell; Hyland, David

    2013-05-01

    Here a modification to the hybrid input-output (HIO) method of phase retrieval is presented which aides in mitigating the negative effects of low signal-to-noise ratios (SNRs). Various type of interferometers measure diffraction patterns which are used to determine the Fourier transform modulus of an objective. Interferometry often suffers from very low SNRs making phase retrieval difficult because of the sensitivity of most phase retrieval algorithms to local minima. Here we analyze the effect of noise on the HIO method. The result is used as a rationale for the proposed modification to the HIO method. The algorithm presented here introduces a filtering scheme which removes much of the Fourier modulus noise. Examples are shown and the results are compared to the HIO method with and without the proposed modification. Comparisons are also made to other methods of filtering the Fourier modulus noise.

  3. Querying Proofs (Work in Progress)

    NASA Technical Reports Server (NTRS)

    Aspinall, David; Denney, Ewen; Lueth, Christoph

    2011-01-01

    We motivate and introduce the basis for a query language designed for inspecting electronic representations of proofs. We argue that there is much to learn from large proofs beyond their validity, and that a dedicated query language can provide a principled way of implementing a family of useful operations.

  4. Data Extraction and Ad Hoc Query of an Entity— Attribute— Value Database

    PubMed Central

    Nadkarni, Prakash M.; Brandt, Cynthia

    1998-01-01

    Entity—attribute—value (EAV) tables form the major component of several mainstream electronic patient record systems (EPRSs). Such systems have been optimized for real-time retrieval of individual patient data. Data warehousing, on the other hand, involves cross-patient data retrieval based on values of patient attributes, with a focus on ad hoc query. Attribute-centric query is inherently more difficult when data are stored in EAV form than when they are stored conventionally. The authors illustrate their approach to the attribute-centric query problem with ACT/DB, a database for managing clinical trials data. This approach is based on metadata supporting a query front end that essentially hides the EAV/non-EAV nature of individual attributes from the user. The authors' work does not close the query problem, and they identify several complex subproblems that are still to be solved. PMID:9824799

  5. The ESIS query environment pilot project

    NASA Technical Reports Server (NTRS)

    Fuchs, Jens J.; Ciarlo, Alessandro; Benso, Stefano

    1993-01-01

    The European Space Information System (ESIS) was originally conceived to provide the European space science community with simple and efficient access to space data archives, facilities with which to examine and analyze the retrieved data, and general information services. To achieve that ESIS will provide the scientists with a discipline specific environment for querying in a uniform and transparent manner data stored in geographically dispersed archives. Furthermore it will provide discipline specific tools for displaying and analyzing the retrieved data. The central concept of ESIS is to achieve a more efficient and wider usage of space scientific data, while maintaining the physical archives at the institutions which created them, and has the best background for ensuring and maintaining the scientific validity and interest of the data. In addition to coping with the physical distribution of data, ESIS is to manage also the heterogenity of the individual archives' data models, formats and data base management systems. Thus the ESIS system shall appear to the user as a single database, while it does in fact consist of a collection of dispersed and locally managed databases and data archives. The work reported in this paper is one of the results of the ESIS Pilot Project which is to be completed in 1993. More specifically it presents the pilot ESIS Query Environment (ESIS QE) system which forms the data retrieval and data dissemination axis of the ESIS system. The others are formed by the ESIS Correlation Environment (ESIS CE) and the ESIS Information Services. The ESIS QE Pilot Project is carried out for the European Space Agency's Research and Information center, ESRIN, by a Consortium consisting of Computer Resources International, Denmark, CISET S.p.a, Italy, the University of Strasbourg, France and the Rutherford Appleton Laboratories in the U.K. Furthermore numerous scientists both within ESA and space science community in Europe have been involved in

  6. Using Induction to Refine Information Retrieval Strategies

    NASA Technical Reports Server (NTRS)

    Baudin, Catherine; Pell, Barney; Kedar, Smadar

    1994-01-01

    Conceptual information retrieval systems use structured document indices, domain knowledge and a set of heuristic retrieval strategies to match user queries with a set of indices describing the document's content. Such retrieval strategies increase the set of relevant documents retrieved (increase recall), but at the expense of returning additional irrelevant documents (decrease precision). Usually in conceptual information retrieval systems this tradeoff is managed by hand and with difficulty. This paper discusses ways of managing this tradeoff by the application of standard induction algorithms to refine the retrieval strategies in an engineering design domain. We gathered examples of query/retrieval pairs during the system's operation using feedback from a user on the retrieved information. We then fed these examples to the induction algorithm and generated decision trees that refine the existing set of retrieval strategies. We found that (1) induction improved the precision on a set of queries generated by another user, without a significant loss in recall, and (2) in an interactive mode, the decision trees pointed out flaws in the retrieval and indexing knowledge and suggested ways to refine the retrieval strategies.

  7. Using Induction to Refine Information Retrieval Strategies

    NASA Technical Reports Server (NTRS)

    Baudin, Catherine; Pell, Barney; Kedar, Smadar

    1994-01-01

    Conceptual information retrieval systems use structured document indices, domain knowledge and a set of heuristic retrieval strategies to match user queries with a set of indices describing the document's content. Such retrieval strategies increase the set of relevant documents retrieved (increase recall), but at the expense of returning additional irrelevant documents (decrease precision). Usually in conceptual information retrieval systems this tradeoff is managed by hand and with difficulty. This paper discusses ways of managing this tradeoff by the application of standard induction algorithms to refine the retrieval strategies in an engineering design domain. We gathered examples of query/retrieval pairs during the system's operation using feedback from a user on the retrieved information. We then fed these examples to the induction algorithm and generated decision trees that refine the existing set of retrieval strategies. We found that (1) induction improved the precision on a set of queries generated by another user, without a significant loss in recall, and (2) in an interactive mode, the decision trees pointed out flaws in the retrieval and indexing knowledge and suggested ways to refine the retrieval strategies.

  8. Modeling the Retrieval Process for an Information Retrieval System Using an Ordinal Fuzzy Linguistic Approach.

    ERIC Educational Resources Information Center

    Herrera-Viedma, E.

    2001-01-01

    Proposes a linguistic model for an Information Retrieval System (IRS) defined using an ordinal fuzzy linguistic approach. The query subsystem accepts Boolean queries with terms weighted by ordinal linguistic values and the evaluation subsystem returns documents arranged in relevance classes labeled with ordinal linguistic values. The system gives…

  9. Web Database Schema Identification through Simple Query Interface

    NASA Astrophysics Data System (ADS)

    Lin, Ling; Zhou, Lizhu

    Web databases provide different types of query interfaces to access the data records stored in the backend databases. While most existing works exploit a complex query interface with multiple input fields to perform schema identification of the Web databases, little attention has been paid on how to identify the schema of web databases by simple query interface (SQI), which has only one single query text input field. This paper proposes a new method of instance-based query probing to identify WDBs' interface and result schema for SQI. The interface schema identification problem is defined as generating the fullcondition query of SQI and a novel query probing strategy is proposed. The result schema is also identified based on the result webpages of SQI's full-condition query, and an extended identification of the non-query attributes is proposed to improve the attribute recall rate. Experimental results on web databases of online shopping for book, movie and mobile phone show that our method is effective and efficient.

  10. Toward integrating text and images for multimedia retrieval in heterogeneous data mining

    NASA Astrophysics Data System (ADS)

    Dua, Sumeet; Mannava, Vinay

    2005-10-01

    The problem of heterogeneous data mining deals with the computational challenges of searching multimedia data in a unified computational framework that can answer similarity queries of data mining by accurate and efficient means. The advances in data collection methodologies have generated large data-warehouses, in assortment of application domains, including but not limited to, Internet applications for multimedia retrieval and exchange. Heterogeneous data indexing has proven to be a valuable tool for complex data mining in large data domains inherently semi-structured in nature. We propose a solution to integrate the feature vectors of image and text by cooperatively representing them in a multidimensional spatial data structure, which has previously exhibited superior search performance in image database domains. We have evaluated results of content-based similarity queries on the indexing schema independently in images and textual domains. We have then studied and represented the effect of the choice of similarity metric on the similarity queries. We then propose an indexing schema that integrates the feature vectors of text and images to answer integrated queries on the unified heterogeneous data space. An added advantage of the proposed methodology is embodied by the fact that a textual feature vector can query a heterogeneous database to retrieve both text as well as images as query results. This solves the problem of individually querying each data-domain separately and sequentially scanning the integrated database for similarity results. The proposed methodology is time and space efficient, and is capable of answering complex heterogeneous data mining queries in multimedia domains.

  11. HDF5-FastQuery: Accelerating Complex Queries on HDF Datasets usingFast Bitmap Indices

    SciTech Connect

    Gosink, Luke; Shalf, John; Stockinger, Kurt; Wu, Kesheng; Bethel,Wes

    2006-03-30

    Large scale scientific data is often stored in scientific data formats such as FITS, netCDF and HDF. These storage formats are of particular interest to the scientific user community since they provide multi-dimensional storage and retrieval. However, one of the drawbacks of these storage formats is that they do not support semantic indexing which is important for interactive data analysis where scientists look for features of interests such as ''Find all supernova explosions where energy > 10{sup 5} and temperature > 10{sup 6}''. In this paper we present a novel approach called HDF5-FastQuery to accelerate the data access of large HDF5 files by introducing multi-dimensional semantic indexing. Our implementation leverages an efficient indexing technology called bitmap indexing that has been widely used in the database community. Bitmap indices are especially well suited for interactive exploration of large-scale read only data. Storing the bitmap indices into the HDF5 file has the following advantages: (a) Significant performance speedup of accessing subsets of multi-dimensional data and (b) portability of the indices across multiple computer platforms. We will present an API that simplifies the execution of queries on HDF5 files for general scientific applications and data analysis. The design is flexible enough to accommodate the use of arbitrary indexing technology for semantic range queries. We will also provide a detailed performance analysis of HDF5-FastQuery for both synthetic and scientific data. The results demonstrate that our proposed approach for multi-dimensional queries is up to a factor of 2 faster than HDF5.

  12. HDF5-FastQuery: Accelerating Complex Queries on HDF Datasets UsingFast Bitmap Indices

    SciTech Connect

    Gosink, Luke; Shalf, John; Stockinger, Kurt; Wu, Kesheng; Bethel,Wes

    2005-12-07

    Large scale scientific data is often stored in scientific data formats such as FITS, netCDF and HDF. These storage formats are of particular interest to the scientific user community since they provide multi-dimensional storage and retrieval. However, one of the drawbacks of these storage formats is that they do not support semantic indexing which is important for interactive data analysis where scientists look for features of interests such as ''Find all supernova explosions where energy >105 and temperature >106''. In this paper we present a novel approach called HDF5-FastQuery to accelerate the data access of large HDF5 files by introducing multi-dimensional semantic indexing. Our implementation leverages an efficient indexing technology called ''bitmapindexing'' that has been widely used in the database community. Bitmapindices are especially well suited for interactive exploration of large-scale read-only data. Storing the bitmap indices into the HDF5 file has the following advantages: (a) Significant performance speedup of accessing subsets of multi-dimensional data and (b) portability of the indices across multiple computer platforms. We will present an API that simplifies the execution of queries on HDF5 files for general scientific applications and data analysis. The design is flexible enough to accommodate the use of arbitrary indexing technology for semantic range queries. We will also provide a detailed performance analysis of HDF5-FastQuery for both synthetic and scientific data. The results demonstrate that our proposed approach for multi-dimensional queries is up to a factor of 2 faster than HDF5.

  13. Autojoin: A Simple Rule Based Query Service for Complex Databases

    NASA Astrophysics Data System (ADS)

    Gaffney, N. I.; Gardner, L.; Brandt, M.

    Most databases used today are no longer flat. While the power of using these more complex data stores is well known, construction of queries can be quite a complex task. Currently this often requires detailed knowledge of the database structure and schema. As we move towards a VO paradigm, users cannot be expected to know the structure of databases, but will need to query them. Databases will need to provide query engines to complete queries automatically given only what the user wants to have returned and any qualifications they place on the query. For years StarView, a database query and data retrieval tool for the Space Telescope Science Institute, relied on a complex third party LISP-based program (QUICK) to construct valid SQL queries for the one database it could query. This limited our ability to support StarView as we could not easily add new rules to the system without completely rebuilding the query engine. Furthermore, QUICK did not have the ability to create SQL that would join tables in different databases (but hosted on the same server). Finally, the cost of upgrading to a new version of QUICK was prohibitively high. Our solution was to develop a rather simple database table driven Perl CGI program which is able to take as its input a skeleton SQL program. This may come from a program or other web page. In the query only the SELECT and user qualified WHERE clause are specified; no FROM or WHERE clause join information is included. The service then returns a fully qualified and syntactically correct query for the host database SQL program that can be used to get the information the user needs. Thus, an additional layer of abstraction for dealing with databases is created, freeing the user from having to know how tables are related in the database. In this paper we discuss the design and algorithm used to make Autojoin work as well as discuss how, when combined with a robust and searchable description of all the fields that can be publicly queried in

  14. Hybrid Filtering in Semantic Query Processing

    ERIC Educational Resources Information Center

    Jeong, Hanjo

    2011-01-01

    This dissertation presents a hybrid filtering method and a case-based reasoning framework for enhancing the effectiveness of Web search. Web search may not reflect user needs, intent, context, and preferences, because today's keyword-based search is lacking semantic information to capture the user's context and intent in posing the search query.…

  15. Hybrid Filtering in Semantic Query Processing

    ERIC Educational Resources Information Center

    Jeong, Hanjo

    2011-01-01

    This dissertation presents a hybrid filtering method and a case-based reasoning framework for enhancing the effectiveness of Web search. Web search may not reflect user needs, intent, context, and preferences, because today's keyword-based search is lacking semantic information to capture the user's context and intent in posing the search query.…

  16. Bio-TDS: bioscience query tool discovery system.

    PubMed

    Gnimpieba, Etienne Z; VanDiermen, Menno S; Gustafson, Shayla M; Conn, Bill; Lushbough, Carol M

    2017-01-04

    Bioinformatics and computational biology play a critical role in bioscience and biomedical research. As researchers design their experimental projects, one major challenge is to find the most relevant bioinformatics toolkits that will lead to new knowledge discovery from their data. The Bio-TDS (Bioscience Query Tool Discovery Systems, http://biotds.org/) has been developed to assist researchers in retrieving the most applicable analytic tools by allowing them to formulate their questions as free text. The Bio-TDS is a flexible retrieval system that affords users from multiple bioscience domains (e.g. genomic, proteomic, bio-imaging) the ability to query over 12 000 analytic tool descriptions integrated from well-established, community repositories. One of the primary components of the Bio-TDS is the ontology and natural language processing workflow for annotation, curation, query processing, and evaluation. The Bio-TDS's scientific impact was evaluated using sample questions posed by researchers retrieved from Biostars, a site focusing on BIOLOGICAL DATA ANALYSIS: The Bio-TDS was compared to five similar bioscience analytic tool retrieval systems with the Bio-TDS outperforming the others in terms of relevance and completeness. The Bio-TDS offers researchers the capacity to associate their bioscience question with the most relevant computational toolsets required for the data analysis in their knowledge discovery process. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. Bio-TDS: bioscience query tool discovery system

    PubMed Central

    Gnimpieba, Etienne Z.; VanDiermen, Menno S.; Gustafson, Shayla M.; Conn, Bill; Lushbough, Carol M.

    2017-01-01

    Bioinformatics and computational biology play a critical role in bioscience and biomedical research. As researchers design their experimental projects, one major challenge is to find the most relevant bioinformatics toolkits that will lead to new knowledge discovery from their data. The Bio-TDS (Bioscience Query Tool Discovery Systems, http://biotds.org/) has been developed to assist researchers in retrieving the most applicable analytic tools by allowing them to formulate their questions as free text. The Bio-TDS is a flexible retrieval system that affords users from multiple bioscience domains (e.g. genomic, proteomic, bio-imaging) the ability to query over 12 000 analytic tool descriptions integrated from well-established, community repositories. One of the primary components of the Bio-TDS is the ontology and natural language processing workflow for annotation, curation, query processing, and evaluation. The Bio-TDS's scientific impact was evaluated using sample questions posed by researchers retrieved from Biostars, a site focusing on biological data analysis. The Bio-TDS was compared to five similar bioscience analytic tool retrieval systems with the Bio-TDS outperforming the others in terms of relevance and completeness. The Bio-TDS offers researchers the capacity to associate their bioscience question with the most relevant computational toolsets required for the data analysis in their knowledge discovery process. PMID:27924016

  18. In-context query reformulation for failing SPARQL queries

    NASA Astrophysics Data System (ADS)

    Viswanathan, Amar; Michaelis, James R.; Cassidy, Taylor; de Mel, Geeth; Hendler, James

    2017-05-01

    Knowledge bases for decision support systems are growing increasingly complex, through continued advances in data ingest and management approaches. However, humans do not possess the cognitive capabilities to retain a bird's-eyeview of such knowledge bases, and may end up issuing unsatisfiable queries to such systems. This work focuses on the implementation of a query reformulation approach for graph-based knowledge bases, specifically designed to support the Resource Description Framework (RDF). The reformulation approach presented is instance-and schema-aware. Thus, in contrast to relaxation techniques found in the state-of-the-art, the presented approach produces in-context query reformulation.

  19. SNUMedinfo at TREC CDS Track 2014: Medical Case-based Retrieval Task

    DTIC Science & Technology

    2014-11-01

    at the TREC Clinical Decision Support track 2014. This task is about medical case- based retrieval. Case description is used as query text . Per each...knowledge-based query expan- sion method for the relevance ranking. Secondly, machine learning classifier based text categorization method is used for the...performance improvements. Keywords: Case-based retrieval, Query expansion, Text categorization, Infor- mation retrieval 1. Introduction In this

  20. Seasonal trends in tinnitus symptomatology: evidence from Internet search engine query data.

    PubMed

    Plante, David T; Ingram, David G

    2015-10-01

    The primary aim of this study was to test the hypothesis that the symptom of tinnitus demonstrates a seasonal pattern with worsening in the winter relative to the summer using Internet search engine query data. Normalized search volume for the term 'tinnitus' from January 2004 through December 2013 was retrieved from Google Trends. Seasonal effects were evaluated using cosinor regression models. Primary countries of interest were the United States and Australia. Secondary exploratory analyses were also performed using data from Germany, the United Kingdom, Canada, Sweden, and Switzerland. Significant seasonal effects for 'tinnitus' search queries were found in the United States and Australia (p < 0.00001 for both countries), with peaks in the winter and troughs in the summer. Secondary analyses demonstrated similarly significant seasonal effects for Germany (p < 0.00001), Canada (p < 0.00001), and Sweden (p = 0.0008), again with increased search volume in the winter relative to the summer. Our findings indicate that there are significant seasonal trends for Internet search queries for tinnitus, with a zenith in winter months. Further research is indicated to determine the biological mechanisms underlying these findings, as they may provide insights into the pathophysiology of this common and debilitating medical symptom.

  1. A Comparison of Two Methods for Boolean Query Relevancy Feedback.

    ERIC Educational Resources Information Center

    Salton, G.; And Others

    1984-01-01

    Evaluates and compares two recently proposed automatic methods for relevance feedback of Boolean queries (Dillon method, which uses probabilistic approach as basis, and disjunctive normal form method). Conclusions are drawn concerning the use of effective feedback methods in a Boolean query environment. Nineteen references are included. (EJS)

  2. Estimating Missing Features to Improve Multimedia Information Retrieval

    SciTech Connect

    Bagherjeiran, A; Love, N S; Kamath, C

    2006-09-28

    Retrieval in a multimedia database usually involves combining information from different modalities of data, such as text and images. However, all modalities of the data may not be available to form the query. The retrieval results from such a partial query are often less than satisfactory. In this paper, we present an approach to complete a partial query by estimating the missing features in the query. Our experiments with a database of images and their associated captions show that, with an initial text-only query, our completion method has similar performance to a full query with both image and text features. In addition, when we use relevance feedback, our approach outperforms the results obtained using a full query.

  3. Sex effects on spatial learning but not on spatial memory retrieval in healthy young adults.

    PubMed

    Piber, Dominique; Nowacki, Jan; Mueller, Sven C; Wingenfeld, Katja; Otte, Christian

    2017-08-25

    Sex differences have been found in spatial learning and spatial memory, with several studies indicating that males outperform females. We tested in the virtual Morris Water Maze (vMWM) task, whether sex differences in spatial cognitive processes are attributable to differences in spatial learning or spatial memory retrieval in a large student sample. We tested 90 healthy students (45 women and 45 men) with a mean age of 23.5 years (SD=3.5). Spatial learning and spatial memory retrieval were measured by using the vMWM task, during which participants had to search a virtual pool for a hidden platform, facilitated by visual cues surrounding the pool. Several learning trials assessed spatial learning, while a separate probe trial assessed spatial memory retrieval. We found a significant sex effect during spatial learning, with males showing shorter latency and shorter path length, as compared to females (all p<0.001). Yet, there was no significant sex effect in spatial memory retrieval (p=0.615). Furthermore, post-hoc analyses revealed significant sex differences in spatial search strategies (p<0.05), but no difference in the number of platform crossings (p=0.375). Our results indicate that in healthy young adults, males show faster spatial learning in a virtual environment, as compared to females. Interestingly, we found no significant sex differences during spatial memory retrieval. Our study raises the question, whether men and women use different learning strategies, which nevertheless result in equal performances of spatial memory retrieval. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Information Retrieval beyond the Text Document.

    ERIC Educational Resources Information Center

    Rui, Yong; Ortega, Michael; Huang, Thomas S.; Mehrotra, Sharad

    1999-01-01

    Reports some of the progress made over the years toward exploring information beyond the text domain. Describes the Multimedia Analysis and Retrieval Systems (MARS), developed to increase access to non-textual information. Addresses the following aspects of MARS: (1) visual feature extraction; (2) retrieval models; (3) query reformulation…

  5. Indexing and Retrieval for the Web.

    ERIC Educational Resources Information Center

    Rasmussen, Edie M.

    2003-01-01

    Explores current research on indexing and ranking as retrieval functions of search engines on the Web. Highlights include measuring search engine stability; evaluation of Web indexing and retrieval; Web crawlers; hyperlinks for indexing and ranking; ranking for metasearch; document structure; citation indexing; relevance; query evaluation;…

  6. Fuzzy Set Theoretical Approach to Document Retrieval.

    ERIC Educational Resources Information Center

    Radecki, Tadeusz

    1979-01-01

    Presents a new method of document retrieval based on the fundamental operations of fuzzy set theory. Basic notions are introduced. Then the syntax and semantics of the proposed language for document retrieval is given, and an algorithm allocating documents to particular queries is described and its properties are discussed. (Author/CWM)

  7. Relation of Resemblance in Information Retrieval.

    ERIC Educational Resources Information Center

    Pietilainen, Pirkko

    1982-01-01

    Presents a method for using the amount of semantic information in search-query terms as a weighting factor in constructing a fuzzy relation of resemblance between retrieved items in information retrieval online. Two tables, two figures, and a reference list accompany the text. (Author/JL)

  8. Indexing and Retrieval for the Web.

    ERIC Educational Resources Information Center

    Rasmussen, Edie M.

    2003-01-01

    Explores current research on indexing and ranking as retrieval functions of search engines on the Web. Highlights include measuring search engine stability; evaluation of Web indexing and retrieval; Web crawlers; hyperlinks for indexing and ranking; ranking for metasearch; document structure; citation indexing; relevance; query evaluation;…

  9. Information Retrieval beyond the Text Document.

    ERIC Educational Resources Information Center

    Rui, Yong; Ortega, Michael; Huang, Thomas S.; Mehrotra, Sharad

    1999-01-01

    Reports some of the progress made over the years toward exploring information beyond the text domain. Describes the Multimedia Analysis and Retrieval Systems (MARS), developed to increase access to non-textual information. Addresses the following aspects of MARS: (1) visual feature extraction; (2) retrieval models; (3) query reformulation…

  10. Multiple Choice Testing and the Retrieval Hypothesis of the Testing Effect

    ERIC Educational Resources Information Center

    Sensenig, Amanda E.

    2010-01-01

    Taking a test often leads to enhanced later memory for the tested information, a phenomenon known as the "testing effect". This memory advantage has been reliably demonstrated with recall tests but not multiple choice tests. One potential explanation for this finding is that multiple choice tests do not rely on retrieval processes to the same…

  11. Paradoxical Effects of Testing: Retrieval Enhances Both Accurate Recall and Suggestibility in Eyewitnesses

    ERIC Educational Resources Information Center

    Chan, Jason C. K.; Langley, Moses M.

    2011-01-01

    Although retrieval practice typically enhances memory retention, it can also impair subsequent eyewitness memory accuracy (Chan, Thomas, & Bulevich, 2009). Specifically, participants who had taken an initial test about a witnessed event were more likely than nontested participants to recall subsequently encountered misinformation--an effect we…

  12. GPU acceleration of melody accurate matching in query-by-humming.

    PubMed

    Xiao, Limin; Zheng, Yao; Tang, Wenqi; Yao, Guangchao; Ruan, Li

    2014-01-01

    With the increasing scale of the melody database, the query-by-humming system faces the trade-offs between response speed and retrieval accuracy. Melody accurate matching is the key factor to restrict the response speed. In this paper, we present a GPU acceleration method for melody accurate matching, in order to improve the response speed without reducing retrieval accuracy. The method develops two parallel strategies (intra-task parallelism and inter-task parallelism) to obtain accelerated effects. The efficiency of our method is validated through extensive experiments. Evaluation results show that our single GPU implementation achieves 20x to 40x speedup ratio, when compared to a typical general purpose CPU's execution time.

  13. GPU Acceleration of Melody Accurate Matching in Query-by-Humming

    PubMed Central

    Xiao, Limin; Zheng, Yao; Tang, Wenqi; Yao, Guangchao; Ruan, Li

    2014-01-01

    With the increasing scale of the melody database, the query-by-humming system faces the trade-offs between response speed and retrieval accuracy. Melody accurate matching is the key factor to restrict the response speed. In this paper, we present a GPU acceleration method for melody accurate matching, in order to improve the response speed without reducing retrieval accuracy. The method develops two parallel strategies (intra-task parallelism and inter-task parallelism) to obtain accelerated effects. The efficiency of our method is validated through extensive experiments. Evaluation results show that our single GPU implementation achieves 20x to 40x speedup ratio, when compared to a typical general purpose CPU's execution time. PMID:24693239

  14. Evaluation of Content-Matched Range Monitoring Queries over Moving Objects in Mobile Computing Environments

    PubMed Central

    Jung, HaRim; Song, MoonBae; Youn, Hee Yong; Kim, Ung Mo

    2015-01-01

    A content-matched (CM) range monitoring query over moving objects continually retrieves the moving objects (i) whose non-spatial attribute values are matched to given non-spatial query values; and (ii) that are currently located within a given spatial query range. In this paper, we propose a new query indexing structure, called the group-aware query region tree (GQR-tree) for efficient evaluation of CM range monitoring queries. The primary role of the GQR-tree is to help the server leverage the computational capabilities of moving objects in order to improve the system performance in terms of the wireless communication cost and server workload. Through a series of comprehensive simulations, we verify the superiority of the GQR-tree method over the existing methods. PMID:26393613

  15. Evaluation of Content-Matched Range Monitoring Queries over Moving Objects in Mobile Computing Environments.

    PubMed

    Jung, HaRim; Song, MoonBae; Youn, Hee Yong; Kim, Ung Mo

    2015-09-18

    A content-matched (CM) rangemonitoring query overmoving objects continually retrieves the moving objects (i) whose non-spatial attribute values are matched to given non-spatial query values; and (ii) that are currently located within a given spatial query range. In this paper, we propose a new query indexing structure, called the group-aware query region tree (GQR-tree) for efficient evaluation of CMrange monitoring queries. The primary role of the GQR-tree is to help the server leverage the computational capabilities of moving objects in order to improve the system performance in terms of the wireless communication cost and server workload. Through a series of comprehensive simulations, we verify the superiority of the GQR-tree method over the existing methods.

  16. Application and Effects of Linguistic Functions on Information Retrieval in a German Language Full-Text Database: Comparison between Retrieval in Abstract and Full Text.

    ERIC Educational Resources Information Center

    Tauchert, Wolfgang; And Others

    1991-01-01

    Describes the PADOK-II project in Germany, which was designed to give information on the effects of linguistic algorithms on retrieval in a full-text database, the German Patent Information System (GPI). Relevance assessments are discussed, statistical evaluations are described, and searches are compared for the full-text section versus the…

  17. Research on Extension of Sparql Ontology Query Language Considering the Computation of Indoor Spatial Relations

    NASA Astrophysics Data System (ADS)

    Li, C.; Zhu, X.; Guo, W.; Liu, Y.; Huang, H.

    2015-05-01

    A method suitable for indoor complex semantic query considering the computation of indoor spatial relations is provided According to the characteristics of indoor space. This paper designs ontology model describing the space related information of humans, events and Indoor space objects (e.g. Storey and Room) as well as their relations to meet the indoor semantic query. The ontology concepts are used in IndoorSPARQL query language which extends SPARQL syntax for representing and querying indoor space. And four types specific primitives for indoor query, "Adjacent", "Opposite", "Vertical" and "Contain", are defined as query functions in IndoorSPARQL used to support quantitative spatial computations. Also a method is proposed to analysis the query language. Finally this paper adopts this method to realize indoor semantic query on the study area through constructing the ontology model for the study building. The experimental results show that the method proposed in this paper can effectively support complex indoor space semantic query.

  18. Statistics Analysis of the Uncertainties in Cloud Optical Depth Retrievals Caused by Three-Dimensional Radiative Effects

    NASA Technical Reports Server (NTRS)

    Varnai, Tamas; Marshak, Alexander

    2000-01-01

    This paper presents a simple approach to estimate the uncertainties that arise in satellite retrievals of cloud optical depth when the retrievals use one-dimensional radiative transfer theory for heterogeneous clouds that have variations in all three dimensions. For the first time, preliminary error bounds are set to estimate the uncertainty of cloud optical depth retrievals. These estimates can help us better understand the nature of uncertainties that three-dimensional effects can introduce into retrievals of this important product of the MODIS instrument. The probability distribution of resulting retrieval errors is examined through theoretical simulations of shortwave cloud reflection for a wide variety of cloud fields. The results are used to illustrate how retrieval uncertainties change with observable and known parameters, such as solar elevation or cloud brightness. Furthermore, the results indicate that a tendency observed in an earlier study, clouds appearing thicker for oblique sun, is indeed caused by three-dimensional radiative effects.

  19. Old/New Effect of Digital Memory Retrieval in Chinese Dyscalculia.

    PubMed

    Wang, Enguo; Du, Chenguang; Ma, Yujun

    This study reports the neurophysiological and behavioral correlates of digital memory retrieval features in Chinese individuals with and without dyscalculia. A total of 18 children with dyscalculia (ages 11.5-13.5) and 18 controls were tested, and their event-related potentials were digitally recorded simultaneously with behavior measurement. Behavioral data showed that the dyscalculia group had lower hit rates and higher false rates than the control group. The electroencephalography results showed that both groups had a significant old/new effect and that this effect was greater in the control group. In the 300 to 400 ms processing stages, both groups showed significant differences in digital memory retrieval in the frontal regions. In the 400 to 500 and 500 to 600 ms epochs, the old/new effect in the control group was significantly greater than it was in the dyscalculia group at the frontal, central, and parietal regions. In the 600 to 700 ms processing stages, both groups showed significant differences in digital memory retrieval in the frontal, central, parietal, and occipital regions. These results suggest that individuals with dyscalculia exhibit impaired digital memory retrieval. Extraction failure may be an important cause of calculation difficulties.

  20. Relativistic quantum private database queries

    NASA Astrophysics Data System (ADS)

    Sun, Si-Jia; Yang, Yu-Guang; Zhang, Ming-Ou

    2015-04-01

    Recently, Jakobi et al. (Phys Rev A 83, 022301, 2011) suggested the first practical private database query protocol (J-protocol) based on the Scarani et al. (Phys Rev Lett 92, 057901, 2004) quantum key distribution protocol. Unfortunately, the J-protocol is just a cheat-sensitive private database query protocol. In this paper, we present an idealized relativistic quantum private database query protocol based on Minkowski causality and the properties of quantum information. Also, we prove that the protocol is secure in terms of the user security and the database security.

  1. The role of economics in the QUERI program: QUERI Series

    PubMed Central

    Smith, Mark W; Barnett, Paul G

    2008-01-01

    Background The United States (U.S.) Department of Veterans Affairs (VA) Quality Enhancement Research Initiative (QUERI) has implemented economic analyses in single-site and multi-site clinical trials. To date, no one has reviewed whether the QUERI Centers are taking an optimal approach to doing so. Consistent with the continuous learning culture of the QUERI Program, this paper provides such a reflection. Methods We present a case study of QUERI as an example of how economic considerations can and should be integrated into implementation research within both single and multi-site studies. We review theoretical and applied cost research in implementation studies outside and within VA. We also present a critique of the use of economic research within the QUERI program. Results Economic evaluation is a key element of implementation research. QUERI has contributed many developments in the field of implementation but has only recently begun multi-site implementation trials across multiple regions within the national VA healthcare system. These trials are unusual in their emphasis on developing detailed costs of implementation, as well as in the use of business case analyses (budget impact analyses). Conclusion Economics appears to play an important role in QUERI implementation studies, only after implementation has reached the stage of multi-site trials. Economic analysis could better inform the choice of which clinical best practices to implement and the choice of implementation interventions to employ. QUERI economics also would benefit from research on costing methods and development of widely accepted international standards for implementation economics. PMID:18430199

  2. Menstrual cycle effects on cortisol responsivity and emotional retrieval following a psychosocial stressor.

    PubMed

    Maki, Pauline M; Mordecai, Kristen L; Rubin, Leah H; Sundermann, Erin; Savarese, Antonia; Eatough, Erin; Drogos, Lauren

    2015-08-01

    This article is part of a Special Issue "Estradiol and cognition". Laboratory-induced stress produces elevations in cortisol and deficits in memory, especially when stress is induced immediately before retrieval of emotionally valent stimuli. Sex and sex steroids appear to influence these stress-induced outcomes, though no study has directly compared the effects of laboratory-induced stress on cortisol and emotional retrieval across the menstrual cycle. We examined the effect of psychosocial stress on cortisol responsivity and emotional retrieval in women tested during either the follicular phase (low estradiol and progesterone) or the luteal phase (higher estradiol and progesterone). Forty women (50% White; age 18-40 years) participated in the study; 20 completed the task during the luteal phase and 20 during the follicular phase. Psychosocial stress was induced with the Trier Social Stress Test (TSST). On the day before the TSST, participants learned two lists of word pairs to 100% criterion. The next day, participants recalled one list after the control condition and the other after the TSST. Women in the follicular phase, but not the luteal phase, demonstrated a significant cortisol response to the TSST. There was a stress-induced decrease in emotional retrieval following the TSST, but this effect was not modified by menstrual phase. However, regression and correlational analyses showed that individual differences in stress-induced cortisol levels were associated with impaired emotional retrieval in the follicular phase only. The present findings indicate that cortisol responsivity and the impairing effects of cortisol on emotional memory are lower when levels of estradiol and progesterone are high compared to when levels are low.

  3. Menstrual cycle effects on cortisol responsivity and emotional retrieval following a psychosocial stressor

    PubMed Central

    Maki, Pauline M.; Mordecai, Kristen L.; Rubin, Leah H.; Sundermann, Erin; Savarese, Antonia; Eatough, Erin; Drogos, Lauren

    2016-01-01

    Laboratory-induced stress produces elevations in cortisol and deficits in memory, especially when stress is induced immediately before retrieval of emotionally valent stimuli. Sex and sex steroids appear to influence these stress-induced outcomes, though no study has directly compared the effects of laboratory-induced stress on cortisol and emotional retrieval across the menstrual cycle. We examined the effect of psychosocial stress on cortisol responsivity and emotional retrieval in women tested during either the follicular phase (low estradiol and progesterone) or the luteal phase (higher estradiol and progesterone). Forty women (50%White; age 18–40 years) participated in the study; 20 completed the task during the luteal phase and 20 during the follicular phase. Psychosocial stress was induced with the Trier Social Stress Test (TSST). On the day before the TSST, participants learned two lists of word pairs to 100% criterion. The next day, participants recalled one list after the control condition and the other after the TSST. Women in the follicular phase, but not the luteal phase, demonstrated a significant cortisol response to the TSST. There was a stress-induced decrease in emotional retrieval following the TSST, but this effect was not modified by menstrual phase. However, regression and correlational analyses showed that individual differences in stress-induced cortisol levels were associated with impaired emotional retrieval in the follicular phase only. The present findings indicate that cortisol responsivity and the impairing effects of cortisol on emotional memory are lower when levels of estradiol and progesterone are high compared to when levels are low. PMID:26187711

  4. Attitude angle effects on Nimbus-7 Scanning Multichannel Microwave Radiometer radiances and geophysical parameter retrievals

    NASA Technical Reports Server (NTRS)

    Macmillan, Daniel S.; Han, Daesoo

    1989-01-01

    The attitude of the Nimbus-7 spacecraft has varied significantly over its lifetime. A summary of the orbital and long-term behavior of the attitude angles and the effects of attitude variations on Scanning Multichannel Microwave Radiometer (SMMR) brightness temperatures is presented. One of the principal effects of these variations is to change the incident angle at which the SMMR views the Earth's surface. The brightness temperatures depend upon the incident angle sensitivities of both the ocean surface emissivity and the atmospheric path length. Ocean surface emissivity is quite sensitive to incident angle variation near the SMMR incident angle, which is about 50 degrees. This sensitivity was estimated theoretically for a smooth ocean surface and no atmosphere. A 1-degree increase in the angle of incidence produces a 2.9 C increase in the retrieved sea surface temperature and a 5.7 m/sec decrease in retrieved sea surface wind speed. An incident angle correction is applied to the SMMR radiances before using them in the geophysical parameter retrieval algorithms. The corrected retrieval data is compared with data obtained without applying the correction.

  5. Analysis of the effectiveness of Sodium Hypochlorite decontamination of cadaveric human tissues at retrieval.

    PubMed

    Paolin, Adolfo; Trojan, Diletta; Carniato, Antonio; Tasca, Fabio; Massarin, Ervino; Tugnoli, Alessandro; Cogliati, Elisa

    2016-12-01

    Bacterial contamination of tissues retrieved from cadaveric donors is a common feature worldwide, and every tissue bank, albeit using different methods, conducts decontamination to guarantee safe tissues suitable for clinical use. The effectiveness of the methods used to eradicate pathogens differs. In order to reduce the tissue bioburden at retrieval, we have introduced a new method involving rinsing tissues in a sodium hypochlorite solution. To test its effectiveness we analyzed two comparable groups of tissues: Group A: 1881 tissues, all rinsed with isotonic saline solution after retrieval, and Group B: 1968 tissues immersed in an isotonic saline solution containing sodium hypochlorite (final concentration 0.1 %) for different lengths of time and subsequently rinsed with isotonic saline. The rinsing solution of each tissue was then sampled for microbiological cultures in both groups. The resultant overall contamination rate was 40.5 % for Group A and 6.7 % for Group B, with an 82.8 % difference in the reduction of contamination between the two groups. This was especially the case for commensal skin bacteria in musculoskeletal tissue, which accounted for over half the overall contamination. Our data highlighted that decontamination with sodium hypochlorite was helpful in reducing the bacterial bioburden in tissues retrieved from cadaveric donors.

  6. Enabling Incremental Query Re-Optimization.

    PubMed

    Liu, Mengmeng; Ives, Zachary G; Loo, Boon Thau

    2016-01-01

    As declarative query processing techniques expand to the Web, data streams, network routers, and cloud platforms, there is an increasing need to re-plan execution in the presence of unanticipated performance changes. New runtime information may affect which query plan we prefer to run. Adaptive techniques require innovation both in terms of the algorithms used to estimate costs, and in terms of the search algorithm that finds the best plan. We investigate how to build a cost-based optimizer that recomputes the optimal plan incrementally given new cost information, much as a stream engine constantly updates its outputs given new data. Our implementation especially shows benefits for stream processing workloads. It lays the foundations upon which a variety of novel adaptive optimization algorithms can be built. We start by leveraging the recently proposed approach of formulating query plan enumeration as a set of recursive datalog queries; we develop a variety of novel optimization approaches to ensure effective pruning in both static and incremental cases. We further show that the lessons learned in the declarative implementation can be equally applied to more traditional optimizer implementations.

  7. Enabling Incremental Query Re-Optimization

    PubMed Central

    Liu, Mengmeng; Ives, Zachary G.; Loo, Boon Thau

    2017-01-01

    As declarative query processing techniques expand to the Web, data streams, network routers, and cloud platforms, there is an increasing need to re-plan execution in the presence of unanticipated performance changes. New runtime information may affect which query plan we prefer to run. Adaptive techniques require innovation both in terms of the algorithms used to estimate costs, and in terms of the search algorithm that finds the best plan. We investigate how to build a cost-based optimizer that recomputes the optimal plan incrementally given new cost information, much as a stream engine constantly updates its outputs given new data. Our implementation especially shows benefits for stream processing workloads. It lays the foundations upon which a variety of novel adaptive optimization algorithms can be built. We start by leveraging the recently proposed approach of formulating query plan enumeration as a set of recursive datalog queries; we develop a variety of novel optimization approaches to ensure effective pruning in both static and incremental cases. We further show that the lessons learned in the declarative implementation can be equally applied to more traditional optimizer implementations. PMID:28659658

  8. Visualizing multidimensional query results using animation

    NASA Astrophysics Data System (ADS)

    Sawant, Amit P.; Healey, Christopher G.

    2008-01-01

    Effective representation of large, complex collections of information (datasets) presents a difficult challenge. Visualization is a solution that uses a visual interface to support efficient analysis and discovery within the data. Our primary goal in this paper is a technique that allows viewers to compare multiple query results representing user-selected subsets of a multidimensional dataset. We present an algorithm that visualizes multidimensional information along a space-filling spiral. Graphical glyphs that vary their position, color, and texture appearance are used to represent attribute values for the data elements in each query result. Guidelines from human perception allow us to construct glyphs that are specifically designed to support exploration, facilitate the discovery of trends and relationships both within and between data elements, and highlight exceptions. A clustering algorithm applied to a user-chosen ranking attribute bundles together similar data elements. This encapsulation is used to show relationships across different queries via animations that morph between query results. We apply our techniques to the MovieLens recommender system, to demonstrate their applicability in a real-world environment, and then conclude with a simple validation experiment to identify the strengths and limitations of our design, compared to a traditional side-by-side visualization.

  9. A Study on Pubmed Search Tag Usage Pattern: Association Rule Mining of a Full-day Pubmed Query Log

    PubMed Central

    2013-01-01

    Background The practice of evidence-based medicine requires efficient biomedical literature search such as PubMed/MEDLINE. Retrieval performance relies highly on the efficient use of search field tags. The purpose of this study was to analyze PubMed log data in order to understand the usage pattern of search tags by the end user in PubMed/MEDLINE search. Methods A PubMed query log file was obtained from the National Library of Medicine containing anonymous user identification, timestamp, and query text. Inconsistent records were removed from the dataset and the search tags were extracted from the query texts. A total of 2,917,159 queries were selected for this study issued by a total of 613,061 users. The analysis of frequent co-occurrences and usage patterns of the search tags was conducted using an association mining algorithm. Results The percentage of search tag usage was low (11.38% of the total queries) and only 2.95% of queries contained two or more tags. Three out of four users used no search tag and about two-third of them issued less than four queries. Among the queries containing at least one tagged search term, the average number of search tags was almost half of the number of total search terms. Navigational search tags are more frequently used than informational search tags. While no strong association was observed between informational and navigational tags, six (out of 19) informational tags and six (out of 29) navigational tags showed strong associations in PubMed searches. Conclusions The low percentage of search tag usage implies that PubMed/MEDLINE users do not utilize the features of PubMed/MEDLINE widely or they are not aware of such features or solely depend on the high recall focused query translation by the PubMed’s Automatic Term Mapping. The users need further education and interactive search application for effective use of the search tags in order to fulfill their biomedical information needs from PubMed/MEDLINE. PMID:23302604

  10. Effective Web and Desktop Retrieval with Enhanced Semantic Spaces

    NASA Astrophysics Data System (ADS)

    Daoud, Amjad M.

    We describe the design and implementation of the NETBOOK prototype system for collecting, structuring and efficiently creating semantic vectors for concepts, noun phrases, and documents from a corpus of free full text ebooks available on the World Wide Web. Automatic generation of concept maps from correlated index terms and extracted noun phrases are used to build a powerful conceptual index of individual pages. To ensure scalabilty of our system, dimension reduction is performed using Random Projection [13]. Furthermore, we present a complete evaluation of the relative effectiveness of the NETBOOK system versus the Google Desktop [8].

  11. Shadows of the past: Temporal retrieval effects in recognition memory

    PubMed Central

    Schwartz, Greg; Howard, Marc W.; Jing, Bing; Kahana, Michael J.

    2008-01-01

    We examine whether temporally defined associations play a role in item recognition. The role of these associations in recall tasks is well-known; we demonstrate an important role in item recognition as well. We find that subjects are significantly more likely to recognize a test item as having been previously experienced if the preceding test item was studied in a temporally proximal list position. Further analyses show that this associative effect is almost entirely due to the highest confidence recognition judgments. PMID:16262777

  12. Mobile medical visual information retrieval.

    PubMed

    Depeursinge, Adrien; Duc, Samuel; Eggel, Ivan; Müller, Henning

    2012-01-01

    In this paper, we propose mobile access to peer-reviewed medical information based on textual search and content-based visual image retrieval. Web-based interfaces designed for limited screen space were developed to query via web services a medical information retrieval engine optimizing the amount of data to be transferred in wireless form. Visual and textual retrieval engines with state-of-the-art performance were integrated. Results obtained show a good usability of the software. Future use in clinical environments has the potential of increasing quality of patient care through bedside access to the medical literature in context.

  13. System For Retrieving Reusable Software

    NASA Technical Reports Server (NTRS)

    Van Warren, Lloyd; Beckman, Brian C.

    1993-01-01

    Encyclopedia of Software Components (ESC) is information-retrieval system of computer hardware and software providing access to generic reusable software tools and parts. Core of ESC is central tool base, which is repository of reusable software. It receives queries and submissions from user through local browser subsystem and receives authorized updates from maintenance subsystem. Sends retrievals to local browser subsystem and user's submissions to maintenance subsystem. Future versions will provide for advanced media, including voice and video, and will link system to database-management system. Programmers will not only retrieve software, but also modify, execute, and cross-link with other software.

  14. QUERI and implementation research: emerging from adolescence into adulthood: QUERI Series.

    PubMed

    Atkins, David

    2009-03-06

    The Quality Enhancement Research Initiative (QUERI) program and implementation research have both come of age in the 10 years since QUERI was established. Looking forward, if QUERI and the field of implementation science are to mature successfully, we will need to address a series of challenges. First, we need to more clearly demonstrate how applying principles of implementation science leads to more effective implementation and communicate those lessons to our partners and funders. Second, we will need to engage in the ongoing debate over methodological standards in quality improvement and implementation research. Third, a program like QUERI needs to become more relevant to the daily decisions of key stakeholders. Fourth, if we hope to sustain interest in implementation science, we will need to demonstrate the business case for more effective implementation. Fifth, we need to think creatively about how to nurture the next generations of implementation researchers and front-line "connectors," who are critical for accelerating implementation. Finally, we need to strengthen the connections between implementation research and the other operational and research activities that influence change in healthcare systems. The excitement of entering adulthood is tempered by the challenge of new responsibilities and expectations. What is essential is that we continue to learn and move forward. For implementation science and for QUERI, the next decade looks to be one filled with exciting possibilities, new partnerships, increasing relevance, and real accomplishment.

  15. The Database Query Support Processor (QSP)

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The number and diversity of databases available to users continues to increase dramatically. Currently, the trend is towards decentralized, client server architectures that (on the surface) are less expensive to acquire, operate, and maintain than information architectures based on centralized, monolithic mainframes. The database query support processor (QSP) effort evaluates the performance of a network level, heterogeneous database access capability. Air Force Material Command's Rome Laboratory has developed an approach, based on ANSI standard X3.138 - 1988, 'The Information Resource Dictionary System (IRDS)' to seamless access to heterogeneous databases based on extensions to data dictionary technology. To successfully query a decentralized information system, users must know what data are available from which source, or have the knowledge and system privileges necessary to find out this information. Privacy and security considerations prohibit free and open access to every information system in every network. Even in completely open systems, time required to locate relevant data (in systems of any appreciable size) would be better spent analyzing the data, assuming the original question was not forgotten. Extensions to data dictionary technology have the potential to more fully automate the search and retrieval for relevant data in a decentralized environment. Substantial amounts of time and money could be saved by not having to teach users what data resides in which systems and how to access each of those systems. Information describing data and how to get it could be removed from the application and placed in a dedicated repository where it belongs. The result simplified applications that are less brittle and less expensive to build and maintain. Software technology providing the required functionality is off the shelf. The key difficulty is in defining the metadata required to support the process. The database query support processor effort will provide

  16. A humming retrieval system based on music fingerprint

    NASA Astrophysics Data System (ADS)

    Han, Xingkai; Cao, Baiyu

    2011-10-01

    In this paper, we proposed an improved music information retrieval method utilizing the music fingerprint. The goal of this method is to represent the music with compressed musical information. Based on the selected MIDI files, which are generated automatically as our music target database, we evaluate the accuracy, effectiveness, and efficiency of this method. In this research we not only extract the feature sequence, which can represent the file effectively, from the query and melody database, but also make it possible for retrieving the results in an innovative way. We investigate on the influence of noise to the performance of our system. As experimental result shows, the retrieval accuracy arriving at up to91% without noise is pretty well

  17. TEQUEL: The query language of SADDLE

    NASA Technical Reports Server (NTRS)

    Rajan, S. D.

    1984-01-01

    A relational database management system is presented that is tailored for engineering applications. A wide variety of engineering data types are supported and the data definition language (DDL) and data manipulation language (DML) are extended to handle matrices. The system can be used either in the standalone mode or through a FORTRAN or PASCAL application program. The query language is of the relational calculus type and allows the user to store, retrieve, update and delete tuples from relations. The relational operations including union, intersect and differ facilitate creation of temporary relations that can be used for manipulating information in a powerful manner. Sample applications are shown to illustrate the creation of data through a FORTRAN program and data manipulation using the TEQUEL DML.

  18. Retrieval intention modulates the effects of directed forgetting instructions on recollection.

    PubMed

    Xiao, Xin; Lucas, Heather D; Paller, Ken A; Ding, Jin-Hong; Guo, Chun-Yan

    2014-01-01

    The neurocognitive basis of memory retrieval is often examined by investigating brain potential old/new effects, which are differences in brain activity between successfully remembered repeated stimuli and correctly rejected new stimuli in a recognition test. In this study, we combined analyses of old/new effects for words with an item-method directed-forgetting manipulation in order to isolate differences between the retrieval processes elicited by words that participants were initially instructed to commit to memory and those that participants were initially instructed to forget. We compared old/new effects elicited by to-be-forgotten (TBF) words with those elicited by to-be-remembered (TBR) words in both an explicit-memory test (a recognition test) and an implicit-memory test (a lexical-decision test). Behavioral results showed clear directed forgetting effects in the recognition test, but not in the lexical decision test. Mirroring the behavioral findings, analyses of brain potentials showed evidence of directed forgetting only in the recognition test. In this test, potentials from 450-650 ms (P600 old/new effects) were more positive for TBR relative to TBF words. By contrast, P600 effects evident during the lexical-decision test did not differ in magnitude between TBR and TBF items. When taken in the context of prior studies that have linked similar parietal old/new effects to the recollection of episodic information, these data suggest that directed-forgetting effects manifest primarily in greater episodic retrieval by TBR than TBF items, and that retrieval intention may be important for these directed-forgetting effects to occur.

  19. Structured Query Language (SQL) fundamentals.

    PubMed

    Jamison, D Curtis

    2003-02-01

    Relational databases provide the most common platform for storing data. The Structured Query Language (SQL) is a powerful tool for interacting with relational database systems. SQL enables the user to concoct complex and powerful queries in a straightforward manner, allowing sophisticated data analysis using simple syntax and structure. This unit demonstrates how to use the MySQL package to build and interact with a relational database.

  20. Quantum search with multiple walk steps per oracle query

    NASA Astrophysics Data System (ADS)

    Wong, Thomas G.; Ambainis, Andris

    2015-08-01

    We identify a key difference between quantum search by discrete- and continuous-time quantum walks: a discrete-time walk typically performs one walk step per oracle query, whereas a continuous-time walk can effectively perform multiple walk steps per query while only counting query time. As a result, we show that continuous-time quantum walks can outperform their discrete-time counterparts, even though both achieve quadratic speedups over their corresponding classical random walks. To provide greater equity, we allow the discrete-time quantum walk to also take multiple walk steps per oracle query while only counting queries. Then it matches the continuous-time algorithm's runtime, but such that it is a cubic speedup over its corresponding classical random walk. This yields a greater-than-quadratic speedup for quantum search over its corresponding classical random walk.

  1. Wave propagation retrieval method for metamaterials: Unambiguous restoration of effective parameters

    NASA Astrophysics Data System (ADS)

    Andryieuski, Andrei; Malureanu, Radu; Lavrinenko, Andrei V.

    2009-11-01

    In this Brief report we propose a direct method of effective-parameters restoration that is based on the wave propagation phenomenon. It is easy in implementation, has no unambiguity in retrieving effective properties and is applicable to thick metamaterial (MTM) slabs. The method is validated on the case studies of fishnet, split cube in carcass, and Jerusalem cross MTMs. The constraints of the method are designated.

  2. On-Line Patient Information System with Query

    PubMed Central

    Hayeck, Elie G.; Berman, William J.; Anné, Antharvedi

    1979-01-01

    Background, current state and future plans for the University of Virginia Biomedical Engineering Division Patient Information System are given. System design is highlighted. When fully implemented, the system will make extensive use of “block transmission,” made for user-computer interaction, for data input, retrieval, and update. Other features will include the possibility of multiple primary keys per patient, frequency distribution, on-line patient query (i.e., search on secondary keys), and general printouts.

  3. Percutaneous Retrieval of Misplaced Intravascular Foreign Objects with the Dormia Basket: An Effective Solution

    SciTech Connect

    Sheth, Rahul Someshwar, Vimal; Warawdekar, Gireesh

    2007-02-15

    Purpose. We report our experience of the retrieval of intravascular foreign body objects by the percutaneous use of the Gemini Dormia basket. Methods. Over a period of 2 years we attempted the percutaneous removal of intravascular foreign bodies in 26 patients. Twenty-six foreign bodies were removed: 8 intravascular stents, 4 embolization coils, 9 guidewires, 1 pacemaker lead, and 4 catheter fragments. The percutaneous retrieval was achieved with a combination of guide catheters and the Gemini Dormia basket. Results. Percutaneous retrieval was successful in 25 of 26 patients (96.2%). It was possible to remove all the intravascular foreign bodies with a combination of guide catheters and the Dormia basket. No complication occurred during the procedure, and no long-term complications were registered during the follow-up period, which ranged from 6 months to 32 months (mean 22.4 months overall). Conclusion. Percutaneous retrieval is an effective and safe technique that should be the first choice for removal of an intravascular foreign body.

  4. The effects of green Ocimum basilicum hydroalcoholic extract on retention and retrieval of memory in mice

    PubMed Central

    Sarahroodi, Shadi; Esmaeili, Somayyeh; Mikaili, Peyman; Hemmati, Zahra; Saberi, Yousof

    2012-01-01

    The purpose of this study was evaluation of green Ocimum basilicum (sweet basil) hydroalcoholic extract on memory retention and retrieval of mice by using passive avoidance apparatus. For this purpose, after weighting, coding and classifying the mice, they were grouped (n = 8) as follow as: test groups (electric shock plus sweet basil extract by doses: 100, 200, 400 and 800 mg/kg, i.p.), control group (Only electric shock) and blank group (electric shock plus normal saline). In all mentioned groups delay time of leaving the platform for both retention and retrieval test of memory was measured. In retention test, sweet basil extract was administered immediately after receiving electric shock and in retrieval test it was administered 24 hours after receiving electric shock. The results indicated that hydroalcoholic extract of green Ocimum basilicum significantly (P < 0.05) increased memory retention. The best response was achieved with 400 mg/Kg of the extract. Also, results showed that sweet basil extract significantly (P < 0.05) increased memory retrieval and the best result was achieved with 400 mg/Kg too. It can be concluded that memory enhancing effects of green Ocimum basilicum is because of antioxidant activity of flavonoids, tannins and terpenoids. PMID:23661866

  5. Effect of Mineral Dust on Ocean Color Retrievals From Space: A Radiative Transfer Simulation Study

    NASA Astrophysics Data System (ADS)

    Ahmad, Z.; Franz, B. A.

    2016-02-01

    In this paper we examine the effect of mineral aerosols (dust) on the retrieval of ocean colors from space. Mineral aerosols are one of the major components of all aerosols found in the earth's atmosphere. These are mainly soil particles that originate from arid and semiarid regions of the world and are blown away by winds thousands of kilometers away from their source regions. The radii of these aerosols are between 0.1 and 1.0 μm and their resident time in the atmosphere is about 21 days. The primary focus of this paper is to estimate the remote sensing reflectance (Rrs) errors in the presence of absorbing aerosols over ocean. The present study is based on radiative transfer (RT) simulations, and it is particularly relevant to ocean color retrievals from sensors like MODIS, MERIS, VIIRS, and the future PACE/OCI. In the simulations, we have used mineralogy to determine the spectral dependence of aerosol refractive index, and modeled the aerosols to represent dust over Cape Verde (Sal Island). As a part of this study, we will present the results for retrieved aerosol optical thickness (τ), Angstrom exponent (α), and remote sensing reflectance (Rrs) and compare them with similar results for non-absorbing aerosols. In addition, we will show how aerosol layer height affects the ocean color retrievals.

  6. Chiral Metamaterials: retrieval of the effective parameters with and without substrate

    SciTech Connect

    Zhao, Rongkuo; Koschny, Thomas; Soukoulis, Costas M.

    2010-06-23

    After the prediction that strong enough optical activity may result in negative refraction and negative reflection, more and more artificial chiral metamaterials were designed and fabricated at difference frequency ranges from microwaves to optical waves. Therefore, a simple and robust method to retrieve the effective constitutive parameters for chiral metamaterials is urgently needed. Here, we analyze the wave propagation in chiral metamaterials and follow the regular retrieval procedure for ordinary metamaterials and apply it in chiral metamaterial slabs. Then based on the transfer matrix technique, the parameter retrieval is extended to treat samples with not only the substrate but also the top layers. After the parameter retrieval procedure, we take two examples to check our method and study how the substrate influences on the thin chiral metamaterials slabs. We find that the substrate may cause the homogeneous slab to be inhomogeneous, i.e. the reflections in forward and backward directions are different. However, the chiral metamaterial where the resonance element is embedded far away from the substrate is insensitive to the substrate.

  7. The effect of spatial resolution upon cloud optical property retrievals. I - Optical thickness

    NASA Technical Reports Server (NTRS)

    Feind, Rand E.; Christopher, Sundar A.; Welch, Ronald M.

    1992-01-01

    High spectral and spatial resolution Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) imagery is used to study the effects of spatial resolution upon fair weather cumulus cloud optical thickness retrievals. As a preprocessing step, a variation of the Gao and Goetz three-band ratio technique is used to discriminate clouds from the background. The combination of the elimination of cloud shadow pixels and using the first derivative of the histogram allows for accurate cloud edge discrimination. The data are progressively degraded from 20 m to 960 m spatial resolution. The results show that retrieved cloud area increases with decreasing spatial resolution. The results also show that there is a monotonic decrease in retrieved cloud optical thickness with decreasing spatial resolution. It is also demonstrated that the use of a single, monospectral reflectance threshold is inadequate for identifying cloud pixels in fair weather cumulus scenes and presumably in any inhomogeneous cloud field. Cloud edges have a distribution of reflectance thresholds. The incorrect identification of cloud edges significantly impacts the accurate retrieval of cloud optical thickness values.

  8. The effects of green Ocimum basilicum hydroalcoholic extract on retention and retrieval of memory in mice.

    PubMed

    Sarahroodi, Shadi; Esmaeili, Somayyeh; Mikaili, Peyman; Hemmati, Zahra; Saberi, Yousof

    2012-04-01

    The purpose of this study was evaluation of green Ocimum basilicum (sweet basil) hydroalcoholic extract on memory retention and retrieval of mice by using passive avoidance apparatus. For this purpose, after weighting, coding and classifying the mice, they were grouped (n = 8) as follow as: test groups (electric shock plus sweet basil extract by doses: 100, 200, 400 and 800 mg/kg, i.p.), control group (Only electric shock) and blank group (electric shock plus normal saline). In all mentioned groups delay time of leaving the platform for both retention and retrieval test of memory was measured. In retention test, sweet basil extract was administered immediately after receiving electric shock and in retrieval test it was administered 24 hours after receiving electric shock. The results indicated that hydroalcoholic extract of green Ocimum basilicum significantly (P < 0.05) increased memory retention. The best response was achieved with 400 mg/Kg of the extract. Also, results showed that sweet basil extract significantly (P < 0.05) increased memory retrieval and the best result was achieved with 400 mg/Kg too. It can be concluded that memory enhancing effects of green Ocimum basilicum is because of antioxidant activity of flavonoids, tannins and terpenoids.

  9. Effects of the M1 muscarinic antagonist dicyclomine on emotional memory retrieval.

    PubMed

    Soares, Juliana Carlota Kramer; Perfetto, Juliano Genaro; Antonio, Bruno Brito; Oliveira, Maria Gabriela Menezes

    2016-02-01

    Extensive research has shown the involvement of the central cholinergic system in the acquisition and consolidation of tasks involving conditioned fear responses, such as those observed in contextual fear conditioning (CFC), tone fear conditioning (TFC) and inhibitory avoidance (IA). However, there are few data concerning the role of this system in the memory retrieval process. Therefore, the present study aimed to compare the effects of the administration of an M1 antagonist on retrieval during these tasks. For each behavioral procedure, groups of male Wistar rats were trained. Twenty-four hr later, they were treated with different doses of dicyclomine (16, 32, or 64 mg/kg, i.p.) or with saline 30 min before the test session. The results showed that dicyclomine at doses of 16 and 32 mg/kg impaired CFC without interfering with IA performance. Moreover, only 64 mg/kg impaired TFC. These data suggest that M1 muscarinic receptors contribute to memory retrieval in CFC and TFC but are not essential for retrieval in IA.

  10. The effect of spatial resolution upon cloud optical property retrievals. I - Optical thickness

    NASA Technical Reports Server (NTRS)

    Feind, Rand E.; Christopher, Sundar A.; Welch, Ronald M.

    1992-01-01

    High spectral and spatial resolution Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) imagery is used to study the effects of spatial resolution upon fair weather cumulus cloud optical thickness retrievals. As a preprocessing step, a variation of the Gao and Goetz three-band ratio technique is used to discriminate clouds from the background. The combination of the elimination of cloud shadow pixels and using the first derivative of the histogram allows for accurate cloud edge discrimination. The data are progressively degraded from 20 m to 960 m spatial resolution. The results show that retrieved cloud area increases with decreasing spatial resolution. The results also show that there is a monotonic decrease in retrieved cloud optical thickness with decreasing spatial resolution. It is also demonstrated that the use of a single, monospectral reflectance threshold is inadequate for identifying cloud pixels in fair weather cumulus scenes and presumably in any inhomogeneous cloud field. Cloud edges have a distribution of reflectance thresholds. The incorrect identification of cloud edges significantly impacts the accurate retrieval of cloud optical thickness values.

  11. Stress and emotional memory retrieval: effects of sex and cortisol response.

    PubMed

    Buchanan, Tony W; Tranel, Daniel

    2008-02-01

    In some situations, memory is enhanced by stressful experience, while in others, it is impaired. The specific components of the stress-response that may result in these differing effects remain unclear, and the current study sought to address this knowledge gap. Forty healthy participants (20 women, 20 men) were exposed to emotionally arousing and neutral pictures. Twenty-four hours later, 20 participants underwent a social stressor (speech and math tests), and 20 underwent a control reading task, both followed by a delayed free recall task. Cortisol responders to the stress condition (5 men and 1 woman) showed reduced memory retrieval for both neutral and emotionally arousing pictures. Men and women in the stress condition who did not produce a cortisol response showed increased retrieval of unpleasant pictures compared to controls. The results provide further evidence that cortisol is a primary effector in the stress-induced memory retrieval deficit. At the same time, stress can enhance memory retrieval performance, especially for emotional stimuli, when the cortisol response is absent.

  12. Investigation of Atmospheric Effects on Retrieval of Sun-Induced Fluorescence Using Hyperspectral Imagery

    PubMed Central

    Ni, Zhuoya; Liu, Zhigang; Li, Zhao-Liang; Nerry, Françoise; Huo, Hongyuan; Sun, Rui; Yang, Peiqi; Zhang, Weiwei

    2016-01-01

    Significant research progress has recently been made in estimating fluorescence in the oxygen absorption bands, however, quantitative retrieval of fluorescence data is still affected by factors such as atmospheric effects. In this paper, top-of-atmosphere (TOA) radiance is generated by the MODTRAN 4 and SCOPE models. Based on simulated data, sensitivity analysis is conducted to assess the sensitivities of four indicators—depth_absorption_band, depth_nofs-depth_withfs, radiance and Fs/radiance—to atmospheric parameters (sun zenith angle (SZA), sensor height, elevation, visibility (VIS) and water content) in the oxygen absorption bands. The results indicate that the SZA and sensor height are the most sensitive parameters and that variations in these two parameters result in large variations calculated as the variation value/the base value in the oxygen absorption depth in the O2-A and O2-B bands (111.4% and 77.1% in the O2-A band; and 27.5% and 32.6% in the O2-B band, respectively). A comparison of fluorescence retrieval using three methods (Damm method, Braun method and DOAS) and SCOPE Fs indicates that the Damm method yields good results and that atmospheric correction can improve the accuracy of fluorescence retrieval. Damm method is the improved 3FLD method but considering atmospheric effects. Finally, hyperspectral airborne images combined with other parameters (SZA, VIS and water content) are exploited to estimate fluorescence using the Damm method and 3FLD method. The retrieval fluorescence is compared with the field measured fluorescence, yielding good results (R2 = 0.91 for Damm vs. SCOPE SIF; R2 = 0.65 for 3FLD vs. SCOPE SIF). Five types of vegetation, including ailanthus, elm, mountain peach, willow and Chinese ash, exhibit consistent associations between the retrieved fluorescence and field measured fluorescence. PMID:27058542

  13. Investigation of Atmospheric Effects on Retrieval of Sun-Induced Fluorescence Using Hyperspectral Imagery.

    PubMed

    Ni, Zhuoya; Liu, Zhigang; Li, Zhao-Liang; Nerry, Françoise; Huo, Hongyuan; Sun, Rui; Yang, Peiqi; Zhang, Weiwei

    2016-04-06

    Significant research progress has recently been made in estimating fluorescence in the oxygen absorption bands, however, quantitative retrieval of fluorescence data is still affected by factors such as atmospheric effects. In this paper, top-of-atmosphere (TOA) radiance is generated by the MODTRAN 4 and SCOPE models. Based on simulated data, sensitivity analysis is conducted to assess the sensitivities of four indicators-depth_absorption_band, depth_nofs-depth_withfs, radiance and Fs/radiance-to atmospheric parameters (sun zenith angle (SZA), sensor height, elevation, visibility (VIS) and water content) in the oxygen absorption bands. The results indicate that the SZA and sensor height are the most sensitive parameters and that variations in these two parameters result in large variations calculated as the variation value/the base value in the oxygen absorption depth in the O₂-A and O₂-B bands (111.4% and 77.1% in the O₂-A band; and 27.5% and 32.6% in the O₂-B band, respectively). A comparison of fluorescence retrieval using three methods (Damm method, Braun method and DOAS) and SCOPE Fs indicates that the Damm method yields good results and that atmospheric correction can improve the accuracy of fluorescence retrieval. Damm method is the improved 3FLD method but considering atmospheric effects. Finally, hyperspectral airborne images combined with other parameters (SZA, VIS and water content) are exploited to estimate fluorescence using the Damm method and 3FLD method. The retrieval fluorescence is compared with the field measured fluorescence, yielding good results (R² = 0.91 for Damm vs. SCOPE SIF; R² = 0.65 for 3FLD vs. SCOPE SIF). Five types of vegetation, including ailanthus, elm, mountain peach, willow and Chinese ash, exhibit consistent associations between the retrieved fluorescence and field measured fluorescence.

  14. Efficient Queries of Stand-off Annotations for Natural Language Processing on Electronic Medical Records

    PubMed Central

    Luo, Yuan; Szolovits, Peter

    2016-01-01

    In natural language processing, stand-off annotation uses the starting and ending positions of an annotation to anchor it to the text and stores the annotation content separately from the text. We address the fundamental problem of efficiently storing stand-off annotations when applying natural language processing on narrative clinical notes in electronic medical records (EMRs) and efficiently retrieving such annotations that satisfy position constraints. Efficient storage and retrieval of stand-off annotations can facilitate tasks such as mapping unstructured text to electronic medical record ontologies. We first formulate this problem into the interval query problem, for which optimal query/update time is in general logarithm. We next perform a tight time complexity analysis on the basic interval tree query algorithm and show its nonoptimality when being applied to a collection of 13 query types from Allen’s interval algebra. We then study two closely related state-of-the-art interval query algorithms, proposed query reformulations, and augmentations to the second algorithm. Our proposed algorithm achieves logarithmic time stabbing-max query time complexity and solves the stabbing-interval query tasks on all of Allen’s relations in logarithmic time, attaining the theoretic lower bound. Updating time is kept logarithmic and the space requirement is kept linear at the same time. We also discuss interval management in external memory models and higher dimensions. PMID:27478379

  15. Efficient Queries of Stand-off Annotations for Natural Language Processing on Electronic Medical Records.

    PubMed

    Luo, Yuan; Szolovits, Peter

    2016-01-01

    In natural language processing, stand-off annotation uses the starting and ending positions of an annotation to anchor it to the text and stores the annotation content separately from the text. We address the fundamental problem of efficiently storing stand-off annotations when applying natural language processing on narrative clinical notes in electronic medical records (EMRs) and efficiently retrieving such annotations that satisfy position constraints. Efficient storage and retrieval of stand-off annotations can facilitate tasks such as mapping unstructured text to electronic medical record ontologies. We first formulate this problem into the interval query problem, for which optimal query/update time is in general logarithm. We next perform a tight time complexity analysis on the basic interval tree query algorithm and show its nonoptimality when being applied to a collection of 13 query types from Allen's interval algebra. We then study two closely related state-of-the-art interval query algorithms, proposed query reformulations, and augmentations to the second algorithm. Our proposed algorithm achieves logarithmic time stabbing-max query time complexity and solves the stabbing-interval query tasks on all of Allen's relations in logarithmic time, attaining the theoretic lower bound. Updating time is kept logarithmic and the space requirement is kept linear at the same time. We also discuss interval management in external memory models and higher dimensions.

  16. Data Discretization for Novel Relationship Discovery in Information Retrieval.

    ERIC Educational Resources Information Center

    Benoit, G.

    2002-01-01

    Describes an information retrieval, visualization, and manipulation model which offers the user multiple ways to exploit the retrieval set, based on weighted query terms, via an interactive interface. Outlines the mathematical model and describes an information retrieval application built on the model to search structured and full-text files.…

  17. Data Discretization for Novel Relationship Discovery in Information Retrieval.

    ERIC Educational Resources Information Center

    Benoit, G.

    2002-01-01

    Describes an information retrieval, visualization, and manipulation model which offers the user multiple ways to exploit the retrieval set, based on weighted query terms, via an interactive interface. Outlines the mathematical model and describes an information retrieval application built on the model to search structured and full-text files.…

  18. The dissociable effects of stereotype threat on older adults' memory encoding and retrieval.

    PubMed

    Krendl, Anne C; Ambady, Nalini; Kensinger, Elizabeth A

    2015-06-01

    The present study asks how subliminal exposure to negative stereotypes about age-related memory deficits affects older adults' memory performance. Whereas prior research has focused on the effect of "stereotype threat" on older adults' memory for neutral material, the present study additionally examines the effect on memory for positive and negative words, as well as whether the subliminal "threat" has a larger impact on memory performance when it occurs prior to encoding or prior to retrieval (as compared to a control condition). Results revealed that older adults' memory impairments were most pronounced when the threat was placed prior to retrieval as compared to when the threat was placed prior to encoding or no threat occurred. Moreover, the threat specifically increased false memory rates, particularly for neutral items compared to positive and negative ones. These results emphasize that stereotype threat effects vary depending upon the phase of memory it impacts.

  19. Age-related effects on the neural correlates of autobiographical memory retrieval.

    PubMed

    St Jacques, Peggy L; Rubin, David C; Cabeza, Roberto

    2012-07-01

    Older adults recall less episodically rich autobiographical memories (AM), however, the neural basis of this effect is not clear. Using functional MRI, we examined the effects of age during search and elaboration phases of AM retrieval. Our results suggest that the age-related attenuation in the episodic richness of AMs is associated with difficulty in the strategic retrieval processes underlying recovery of information during elaboration. First, age effects on AM activity were more pronounced during elaboration than search, with older adults showing less sustained recruitment of the hippocampus and ventrolateral prefrontal cortex (VLPFC) for less episodically rich AMs. Second, there was an age-related reduction in the modulation of top-down coupling of the VLPFC on the hippocampus for episodically rich AMs. In sum, the present study shows that changes in the sustained response and coupling of the hippocampus and prefrontal cortex (PFC) underlie age-related reductions in episodic richness of the personal past.

  20. The effects of aging on ERP correlates of source memory retrieval for self-referential information.

    PubMed

    Dulas, Michael R; Newsome, Rachel N; Duarte, Audrey

    2011-03-04

    Numerous behavioral studies have suggested that normal aging negatively affects source memory accuracy for various kinds of associations. Neuroimaging evidence suggests that less efficient retrieval processing (temporally delayed and attenuated) may contribute to these impairments. Previous aging studies have not compared source memory accuracy and corresponding neural activity for different kinds of source details; namely, those that have been encoded via a more or less effective strategy. Thus, it is not yet known whether encoding source details in a self-referential manner, a strategy suggested to promote successful memory in the young and old, may enhance source memory accuracy and reduce the commonly observed age-related changes in neural activity associated with source memory retrieval. Here, we investigated these issues by using event-related potentials (ERPs) to measure the effects of aging on the neural correlates of successful source memory retrieval ("old-new effects") for objects encoded either self-referentially or self-externally. Behavioral results showed that both young and older adults demonstrated better source memory accuracy for objects encoded self-referentially. ERP results showed that old-new effects onsetted earlier for self-referentially encoded items in both groups and that age-related differences in the onset latency of these effects were reduced for self-referentially, compared to self-externally, encoded items. These results suggest that the implementation of an effective encoding strategy, like self-referential processing, may lead to more efficient retrieval, which in turn may improve source memory accuracy in both young and older adults.

  1. Regional specificity of age effects on the neural correlates of episodic retrieval.

    PubMed

    Duverne, S; Habibi, A; Rugg, M D

    2008-12-01

    We investigated age-related differences in episodic retrieval using a source memory procedure. Age-related differences in retrieval-related activity were analyzed in conditions where source recollection performance was statistically equivalent in young and older subjects. Analyses of BOLD activity revealed a network of regions where recollection effects were equivalent in magnitude in the two age groups. There were no regions where these effects were of greater magnitude in young than in older subjects. In some regions, however, there was a crossover interaction, such that retrieval-related effects reversed in direction between the two age groups. Further analyses of these interactions revealed a dissociation between a posterior hippocampal region where recollection-related activity was confined to the older group, and right fusiform and occipital regions where, in the young group only, activity elicited by studied items was of lower magnitude than activity to new items. We interpret the first of these age-related effects as an example of 'over-recruitment' in response to decline in neural efficiency, and discuss whether the second effect indexes an age-related decline in repetition priming.

  2. Effects of imitating gestures during encoding or during retrieval of novel verbs on children's test performance.

    PubMed

    de Nooijer, Jacqueline A; van Gog, Tamara; Paas, Fred; Zwaan, Rolf A

    2013-09-01

    Research has shown that observing and imitating gestures can foster word learning and that imitation might be more beneficial than observation, which is in line with theories of Embodied Cognition. This study investigated when imitation of gestures is most effective, using a 2×2×2×3 mixed design with between-subjects factors Imitation during Encoding (IE; Yes/No) and Imitation during Retrieval (IR; Yes/No), and within-subjects factors Time of Testing (Immediate/Delayed) and Verb Type (Object manipulation/Locomotion/Abstract). Primary school children (N=115) learned 15 novel verbs (five of each type). They were provided with a verbal definition and a video of the gesture. Depending on assigned condition, they additionally received no imitation instructions, instructions to imitate the gesture immediately (i.e., during encoding; IE), instructions to imitate (from memory) during the first posttest (i.e., during retrieval; IR), or both (IE-IR). Based on the literature, all three imitation conditions could be predicted to be more effective than no imitation. On an immediate and delayed posttest, only the object-manipulation verbs were differentially affected by instructional method, with IE and IR being more effective than no imitation on the immediate test; IE-IR and no imitation did not differ significantly. After a one week delay, only IR was more effective than no imitation, suggesting that imitation during retrieval is most effective for learning object-manipulation words.

  3. The Two Faces of Selective Memory Retrieval: Recall Specificity of the Detrimental but Not the Beneficial Effect

    ERIC Educational Resources Information Center

    Bäuml, Karl-Heinz T.; Dobler, Ina M.

    2015-01-01

    Depending on the degree to which the original study context is accessible, selective memory retrieval can be detrimental or beneficial for the recall of other memories (Bäuml & Samenieh, 2012). Prior work has shown that the detrimental effect of memory retrieval is typically recall specific and does not arise after restudy trials, whereas…

  4. The Two Faces of Selective Memory Retrieval: Recall Specificity of the Detrimental but Not the Beneficial Effect

    ERIC Educational Resources Information Center

    Bäuml, Karl-Heinz T.; Dobler, Ina M.

    2015-01-01

    Depending on the degree to which the original study context is accessible, selective memory retrieval can be detrimental or beneficial for the recall of other memories (Bäuml & Samenieh, 2012). Prior work has shown that the detrimental effect of memory retrieval is typically recall specific and does not arise after restudy trials, whereas…

  5. Surface and Atmospheric Parameter Retrieval From AVIRIS Data: The Importance of Non-Linear Effects

    NASA Technical Reports Server (NTRS)

    Green Robert O.; Moreno, Jose F.

    1996-01-01

    AVIRIS data represent a new and important approach for the retrieval of atmospheric and surface parameters from optical remote sensing data. Not only as a test for future space systems, but also as an operational airborne remote sensing system, the development of algorithms to retrieve information from AVIRIS data is an important step to these new approaches and capabilities. Many things have been learned since AVIRIS became operational, and the successive technical improvements in the hardware and the more sophisticated calibration techniques employed have increased the quality of the data to the point of almost meeting optimum user requirements. However, the potential capabilities of imaging spectrometry over the standard multispectral techniques have still not been fully demonstrated. Reasons for this are the technical difficulties in handling the data, the critical aspect of calibration for advanced retrieval methods, and the lack of proper models with which to invert the measured AVIRIS radiances in all the spectral channels. To achieve the potential of imaging spectrometry, these issues must be addressed. In this paper, an algorithm to retrieve information about both atmospheric and surface parameters from AVIRIS data, by using model inversion techniques, is described. Emphasis is put on the derivation of the model itself as well as proper inversion techniques, robust to noise in the data and an inadequate ability of the model to describe natural variability in the data. The problem of non-linear effects is addressed, as it has been demonstrated to be a major source of error in the numerical values retrieved by more simple, linear-based approaches. Non-linear effects are especially critical for the retrieval of surface parameters where both scattering and absorption effects are coupled, as well as in the cases of significant multiple-scattering contributions. However, sophisticated modeling approaches can handle such non-linear effects, which are especially

  6. Surface and Atmospheric Parameter Retrieval From AVIRIS Data: The Importance of Non-Linear Effects

    NASA Technical Reports Server (NTRS)

    Green Robert O.; Moreno, Jose F.

    1996-01-01

    AVIRIS data represent a new and important approach for the retrieval of atmospheric and surface parameters from optical remote sensing data. Not only as a test for future space systems, but also as an operational airborne remote sensing system, the development of algorithms to retrieve information from AVIRIS data is an important step to these new approaches and capabilities. Many things have been learned since AVIRIS became operational, and the successive technical improvements in the hardware and the more sophisticated calibration techniques employed have increased the quality of the data to the point of almost meeting optimum user requirements. However, the potential capabilities of imaging spectrometry over the standard multispectral techniques have still not been fully demonstrated. Reasons for this are the technical difficulties in handling the data, the critical aspect of calibration for advanced retrieval methods, and the lack of proper models with which to invert the measured AVIRIS radiances in all the spectral channels. To achieve the potential of imaging spectrometry, these issues must be addressed. In this paper, an algorithm to retrieve information about both atmospheric and surface parameters from AVIRIS data, by using model inversion techniques, is described. Emphasis is put on the derivation of the model itself as well as proper inversion techniques, robust to noise in the data and an inadequate ability of the model to describe natural variability in the data. The problem of non-linear effects is addressed, as it has been demonstrated to be a major source of error in the numerical values retrieved by more simple, linear-based approaches. Non-linear effects are especially critical for the retrieval of surface parameters where both scattering and absorption effects are coupled, as well as in the cases of significant multiple-scattering contributions. However, sophisticated modeling approaches can handle such non-linear effects, which are especially

  7. The effect of psilocin on memory acquisition, retrieval, and consolidation in the rat.

    PubMed

    Rambousek, Lukas; Palenicek, Tomas; Vales, Karel; Stuchlik, Ales

    2014-01-01

    The involvement of the serotonin system in the pathophysiology of schizophrenia has been elucidated by experiments with hallucinogens. Application of a hallucinogen to humans leads to changes in perception, cognition, emotions, and induction of psychotic-like symptoms that resemble symptoms of schizophrenia. In rodent studies, their acute administration affects sensorimotor gating, locomotor activity, social behavior, and cognition including working memory, the phenotypes are considered as an animal model of schizophrenia. The complexity and singularity of human cognition raises questions about the validity of animal models utilizing agonists of 5-HT2A receptors. The present study thus investigated the effect of psilocin on memory acquisition, reinforced retrieval, and memory consolidation in rats. Psilocin is a main metabolite of psilocybin acting as an agonist at 5-HT2A receptors with a contribution of 5-HT2C and 5-HT1A receptors. First, we tested the effect of psilocin on the acquisition of a Carousel maze, a spatial task requiring navigation using distal cues, attention, and cognitive coordination. Psilocin significantly impaired the acquisition of the Carousel maze at both doses (1 and 4 mg/kg). The higher dose of psilocin blocked the learning processes even in an additional session when the rats received only saline. Next, we examined the effect of psilocin on reinforced retrieval and consolidation in the Morris water maze (MWM). The dose of 4 mg/kg disrupted reinforced retrieval in the MWM. However, the application of a lower dose was without any significant effect. Finally, neither the low nor high dose of psilocin injected post-training caused a deficit in memory consolidation in the MWM. Taken together, the psilocin dose dependently impaired the acquisition of the Carousel maze and reinforced retrieval in MWM; however, it had no effect on memory consolidation.

  8. Melody Alignment and Similarity Metric for Content-Based Music Retrieval

    NASA Astrophysics Data System (ADS)

    Zhu, Yongwei; Kankanhalli, Mohan S.

    2003-01-01

    Music query-by-humming has attracted much research interest recently. It is a challenging problem since the hummed query inevitably contains much variation and inaccuracy. Furthermore, the similarity computation between the query tune and the reference melody is not easy due to the difficulty in ensuring proper alignment. This is because the query tune can be rendered at an unknown speed and it is usually an arbitrary subsequence of the target reference melody. Many of the previous methods, which adopt note segmentation and string matching, suffer drastically from the errors in the note segmentation, which affects retrieval accuracy and efficiency. Some methods solve the alignment issue by controlling the speed of the articulation of queries, which is inconvenient because it forces users to hum along a metronome. Some other techniques introduce arbitrary rescaling in time but this is computationally very inefficient. In this paper, we introduce a melody alignment technique, which addresses the robustness and efficiency issues. We also present a new melody similarity metric, which is performed directly on melody contours of the query data. This approach cleanly separates the alignment and similarity measurement in the search process. We show how to robustly and efficiently align the query melody with the reference melodies and how to measure the similarity subsequently. We have carried out extensive experiments. Our melody alignment method can reduce the matching candidate to 1.7% with 95% correct alignment rate. The overall retrieval system achieved 80% recall in the top 10 rank list. The results demonstrate the robustness and effectiveness the proposed methods.

  9. Hierarchical Fuzzy Feature Similarity Combination for Presentation Slide Retrieval

    NASA Astrophysics Data System (ADS)

    Kushki, A.; Ajmal, M.; Plataniotis, K. N.

    2009-12-01

    This paper proposes a novel XML-based system for retrieval of presentation slides to address the growing data mining needs in presentation archives for educational and scholarly settings. In particular, contextual information, such as structural and formatting features, is extracted from the open format XML representation of presentation slides. In response to a textual user query, each extracted feature is used to compute a fuzzy relevance score for each slide in the database. The fuzzy scores from the various features are then combined through a hierarchical scheme to generate a single relevance score per slide. Various fusion operators and their properties are examined with respect to their effect on retrieval performance. Experimental results indicate a significant increase in retrieval performance measured in terms of precision-recall. The improvements are attributed to both the incorporation of the contextual features and the hierarchical feature combination scheme.

  10. Human Motion Retrieval Based on Statistical Learning and Bayesian Fusion

    PubMed Central

    Xiao, Qinkun; Song, Ren

    2016-01-01

    A novel motion retrieval approach based on statistical learning and Bayesian fusion is presented. The approach includes two primary stages. (1) In the learning stage, fuzzy clustering is utilized firstly to get the representative frames of motions, and the gesture features of the motions are extracted to build a motion feature database. Based on the motion feature database and statistical learning, the probability distribution function of different motion classes is obtained. (2) In the motion retrieval stage, the query motion feature is extracted firstly according to stage (1). Similarity measurements are then conducted employing a novel method that combines category-based motion similarity distances with similarity distances based on canonical correlation analysis. The two motion distances are fused using Bayesian estimation, and the retrieval results are ranked according to the fused values. The effectiveness of the proposed method is verified experimentally. PMID:27732673

  11. Results in Computational Geometry: Geometric Embeddings and Query- Retrieval Problems

    DTIC Science & Technology

    1990-11-01

    D. Bolker. Generalized dirichlet tesselations. Geometriae Dedicata, 20:209-243, 1986. [5] F. Aurenhammer. Power diagrams: properties, algorithms, and...voronoi diagrams. Geometriae Dedicata, 27:65-75, 1988. [9] V. E. Benes. Optimal rearrangeable multistage connecting networks. Bell System Technical

  12. Policy Compliance of Queries for Private Information Retrieval

    DTIC Science & Technology

    2010-11-01

    include the use of formalisms that can express realistic data-use policies, automated reasoning engines that can interpret those policies... formalisms that can express realistic data-use policies, automated reasoning engines that can interpret those policies and automatically determine...reasonably well understood by individuals with no prior knowledge of the project and identified as a potential method by which the government could fulfill

  13. Autocorrelation and Regularization of Query-Based Information Retrieval Scores

    DTIC Science & Technology

    2008-02-01

    hard clustering is the hard k - means algorithm . Hard clustering techniques limit a document to a single, discrete cluster label. However, documents rarely...53 5.4 Local Score Regularization Algorithm . Inputs are ñ, y, k , and α. The output is the a...For each value of α, we selected the values for k and t maximizing mean average precision. A higher value for α results in more aggressive

  14. Research on the effect of Aerosol on the retrieval of hyperspectral XCO2

    NASA Astrophysics Data System (ADS)

    Gao, Meng; Zhang, Chunmin; Zhou, Yueming

    2017-02-01

    CO2, the greenhouse gas, is the important one of atmospheric trace gases. The accurate observation of CO2 has great significance for the study of climate warming and global carbon cycle. In this paper, SCIATRAN radiation transfer model is simulated to study the effect of the aerosol parameters to the retrieval precision of XCO2.The absorption band of CO2 at 1.61um and O2-A are selected to analyse the sensitivity of aerosol parameters. The absolute error and relative error about the main aerosol parameters, optical thickness and scattering phase function are analyzed. It provides basis on the effective debugging for the model, plays an important role in the improvement of the precision of XCO2 retrieval.

  15. Ease of Retrieval Effects on Relationship Commitment: The Role of Future Plans.

    PubMed

    Tan, Kenneth; Agnew, Christopher R

    2016-02-01

    How do perceptions of future romantic plans affect close relationships? In three studies, we examined the effects of ease of retrieval of future plans on romantic relationship commitment. We hypothesized that greater ease of retrieval would be associated with greater relationship commitment among those who were high in need for cognition. Study 1 participants listed either two or 10 future plans and completed a measure assessing need for cognition. Results showed that high need for cognition individuals asked to list two instead of 10 future plans reported greater commitment, but those low in need for cognition showed the opposite pattern. Study 2 replicated this effect while controlling for plan substitutability. Study 3 examined the mediational role of commitment doubt. Those high in need for cognition listing more plans had more doubts and reported lower commitment. These findings suggest that perceptions of future plans can influence relationship commitment under specific conditions.

  16. Decomposition: A Strategy for Query Processing.

    ERIC Educational Resources Information Center

    Wong, Eugene; Youssefi, Karel

    Multivariable queries can be processed in the data base management system INGRES. The general procedure is to decompose the query into a sequence of one-variable queries using two processes. One process is reduction which requires breaking off components of the query which are joined to it by a single variable. The other process,…

  17. Mining Longitudinal Web Queries: Trends and Patterns.

    ERIC Educational Resources Information Center

    Wang, Peiling; Berry, Michael W.; Yang, Yiheng

    2003-01-01

    Analyzed user queries submitted to an academic Web site during a four-year period, using a relational database, to examine users' query behavior, to identify problems they encounter, and to develop techniques for optimizing query analysis and mining. Linguistic analyses focus on query structures, lexicon, and word associations using statistical…

  18. Effects of context and word class on lexical retrieval in Chinese speakers with anomic aphasia.

    PubMed

    Law, Sam-Po; Kong, Anthony Pak-Hin; Lai, Loretta Wing-Shan; Lai, Christy

    2015-01-01

    Differences in processing nouns and verbs have been investigated intensely in psycholinguistics and neuropsychology in past decades. However, the majority of studies examining retrieval of these word classes have involved tasks of single word stimuli or responses. While the results have provided rich information for addressing issues about grammatical class distinctions, it is unclear whether they have adequate ecological validity for understanding lexical retrieval in connected speech which characterizes daily verbal communication. Previous investigations comparing retrieval of nouns and verbs in single word production and connected speech have reported either discrepant performance between the two contexts with presence of word class dissociation in picture naming but absence in connected speech, or null effects of word class. In addition, word finding difficulties have been found to be less severe in connected speech than picture naming. However, these studies have failed to match target stimuli of the two word classes and between tasks on psycholinguistic variables known to affect performance in response latency and/or accuracy. The present study compared lexical retrieval of nouns and verbs in picture naming and connected speech from picture description, procedural description, and story-telling among 19 Chinese speakers with anomic aphasia and their age, gender, and education matched healthy controls, to understand the influence of grammatical class on word production across speech contexts when target items were balanced for confounding variables between word classes and tasks. Elicitation of responses followed the protocol of the AphasiaBank consortium (http://talkbank.org/AphasiaBank/). Target words for confrontation naming were based on well-established naming tests, while those for narrative were drawn from a large database of normal speakers. Selected nouns and verbs in the two contexts were matched for age-of-acquisition (AoA) and familiarity

  19. Effects of context and word class on lexical retrieval in Chinese speakers with anomic aphasia

    PubMed Central

    Law, Sam-Po; Kong, Anthony Pak-Hin; Lai, Loretta Wing-Shan; Lai, Christy

    2014-01-01

    Background Differences in processing nouns and verbs have been investigated intensely in psycholinguistics and neuropsychology in past decades. However, the majority of studies examining retrieval of these word classes have involved tasks of single word stimuli or responses. While the results have provided rich information for addressing issues about grammatical class distinctions, it is unclear whether they have adequate ecological validity for understanding lexical retrieval in connected speech which characterizes daily verbal communication. Previous investigations comparing retrieval of nouns and verbs in single word production and connected speech have reported either discrepant performance between the two contexts with presence of word class dissociation in picture naming but absence in connected speech, or null effects of word class. In addition, word finding difficulties have been found to be less severe in connected speech than picture naming. However, these studies have failed to match target stimuli of the two word classes and between tasks on psycholinguistic variables known to affect performance in response latency and/or accuracy. Aims The present study compared lexical retrieval of nouns and verbs in picture naming and connected speech from picture description, procedural description, and story-telling among 19 Chinese speakers with anomic aphasia and their age, gender, and education matched healthy controls, to understand the influence of grammatical class on word production across speech contexts when target items were balanced for confounding variables between word classes and tasks. Methods & Procedures Elicitation of responses followed the protocol of the AphasiaBank consortium (http://talkbank.org/AphasiaBank/). Target words for confrontation naming were based on well-established naming tests, while those for narrative were drawn from a large database of normal speakers. Selected nouns and verbs in the two contexts were matched for age

  20. Laterality effects in functional connectivity of the angular gyrus during rest and episodic retrieval.

    PubMed

    Bellana, Buddhika; Liu, Zhongxu; Anderson, John A E; Moscovitch, Morris; Grady, Cheryl L

    2016-01-08

    The angular gyrus (AG) is consistently reported in neuroimaging studies of episodic memory retrieval and is a fundamental node within the default mode network (DMN). Its specific contribution to episodic memory is debated, with some suggesting it is important for the subjective experience of episodic recollection, rather than retrieval of objective episodic details. Across studies of episodic retrieval, the left AG is recruited more reliably than the right. We explored functional connectivity of the right and left AG with the DMN during rest and retrieval to assess whether connectivity could provide insight into the nature of this laterality effect. Using data from the publically available 1000 Functional Connectome Project, 8min of resting fMRI data from 180 healthy young adults were analysed. Whole-brain functional connectivity at rest was measured using a seed-based Partial Least Squares (seed-PLS) approach (McIntosh and Lobaugh, 2004) with bilateral AG seeds. A subsequent analysis used 6-min of rest and 6-min of unconstrained, silent retrieval of autobiographical events from a new sample of 20 younger adults. Analysis of this dataset took a more targeted approach to functional connectivity analysis, consisting of univariate pairwise correlations restricted to nodes of the DMN. The seed-PLS analysis resulted in two Latent Variables that together explained ~86% of the shared cross-block covariance. The first LV revealed a common network consistent with the DMN and engaging the AG bilaterally, whereas the second LV revealed a less robust, yet significant, laterality effect in connectivity - the left AG was more strongly connected to the DMN. Univariate analyses of the second sample again revealed better connectivity between the left AG and the DMN at rest. However, during retrieval the left AG was more strongly connected than the right to non-medial temporal (MTL) nodes of the DMN, and MTL nodes were more strongly connected to the right AG. The multivariate

  1. The two faces of selective memory retrieval: recall specificity of the detrimental but not the beneficial effect.

    PubMed

    Bäuml, Karl-Heinz T; Dobler, Ina M

    2015-01-01

    Depending on the degree to which the original study context is accessible, selective memory retrieval can be detrimental or beneficial for the recall of other memories (Bäuml & Samenieh, 2012). Prior work has shown that the detrimental effect of memory retrieval is typically recall specific and does not arise after restudy trials, whereas recall specificity of the beneficial effect has not been examined to date. Addressing the issue, we compared in 2 experiments the effects of retrieval and restudy on recall of other items, when access to the study context was (largely) maintained and when access to the study context was impaired (in Experiment 1 by using the listwise directed-forgetting task, in Experiment 2 by using a prolonged retention interval). In both experiments, selective retrieval but not restudy induced forgetting of other items when context access was maintained, which replicates prior work. In contrast, when context access was impaired, both selective retrieval and restudy induced beneficial effects on other memories. These findings suggest that the detrimental but not the beneficial effect of selective memory retrieval is recall specific. The results are consistent with a recent 2-factor account of selective memory retrieval that attributes the detrimental effect to inhibition or blocking but the beneficial effect to context reactivation processes. PsycINFO Database Record (c) 2015 APA, all rights reserved.

  2. An Efficient Algorithm for Maximizing Range Sum Queries in a Road Network

    PubMed Central

    Jung, HaRim; Kim, Ung-Mo

    2014-01-01

    Given a set of positive-weighted points and a query rectangle r (specified by a client) of given extents, the goal of a maximizing range sum (MaxRS) query is to find the optimal location of r such that the total weights of all the points covered by r are maximized. All existing methods for processing MaxRS queries assume the Euclidean distance metric. In many location-based applications, however, the motion of a client may be constrained by an underlying (spatial) road network; that is, the client cannot move freely in space. This paper addresses the problem of processing MaxRS queries in a road network. We propose the external-memory algorithm that is suited for a large road network database. In addition, in contrast to the existing methods, which retrieve only one optimal location, our proposed algorithm retrieves all the possible optimal locations. Through simulations, we evaluate the performance of the proposed algorithm. PMID:25152915

  3. Effect of Precipitation to the Wind Retrieval from Synthetic Aperture Radar

    NASA Astrophysics Data System (ADS)

    Yu, Shui; Yang, Jingsong; He, Shuangyan; He, Zhiguo; Ren, Lin

    2016-08-01

    As one of the most powerful air-sea interaction in the weather system, typhoon always accompany with a wide range of heavy rainfall. Synthetic Aperture Radar(SAR) plays an important role in typhoon wind field retrieval, because it can work all-day, all-weather and has high spatial resolution. But due to the influence of the rainfall on the radar signal, the inversion precision of sea surface wind field will decline. With the exploration of high wind speed inversion model, much more researchers focus on the influence of large precipitation to the wind field retrieval. Researchers have proposed many different rain effect models applied to scatterometer data, but it is not sure weather they can also used on SAR data.In this paper, one C band scatterometer rain effect model proposed by Congling Nie and David G. Long (TGRS 2007) was applied on typhoon Rammasun RADARSAT-2 ASAR data. Combined with the sea wind direction information from European Center for Medium-Range Weather Forecasts (ECMWF) reanalysis data, high accuracy and high-resolution wind field was obtained by using geophysical model function CMOD5.Then the result was validated with wind field retrieved from VH polarization data using C-band Cross-Polarization Ocean (C-2PO) model (Biao Zhang and William Perrie, AMS, 2012), the comparison showed that there still need further correction based on by Nie and Long's rain effect model.

  4. Prior perceptual processing enhances the effect of emotional arousal on the neural correlates of memory retrieval

    PubMed Central

    Dew, Ilana T. Z.; Ritchey, Maureen; LaBar, Kevin S.; Cabeza, Roberto

    2014-01-01

    A fundamental idea in memory research is that items are more likely to be remembered if encoded with a semantic, rather than perceptual, processing strategy. Interestingly, this effect has been shown to reverse for emotionally arousing materials, such that perceptual processing enhances memory for emotional information or events. The current fMRI study investigated the neural mechanisms of this effect by testing how neural activations during emotional memory retrieval are influenced by the prior encoding strategy. Participants incidentally encoded emotional and neutral pictures under instructions to attend to either semantic or perceptual properties of each picture. Recognition memory was tested two days later. fMRI analyses yielded three main findings. First, right amygdalar activity associated with emotional memory strength was enhanced by prior perceptual processing. Second, prior perceptual processing of emotional pictures produced a stronger effect on recollection- than familiarity-related activations in the right amygdala and left hippocampus. Finally, prior perceptual processing enhanced amygdalar connectivity with regions strongly associated with retrieval success, including hippocampal/parahippocampal regions, visual cortex, and ventral parietal cortex. Taken together, the results specify how encoding orientations yield alterations in brain systems that retrieve emotional memories. PMID:24380867

  5. Prior perceptual processing enhances the effect of emotional arousal on the neural correlates of memory retrieval.

    PubMed

    Dew, Ilana T Z; Ritchey, Maureen; LaBar, Kevin S; Cabeza, Roberto

    2014-07-01

    A fundamental idea in memory research is that items are more likely to be remembered if encoded with a semantic, rather than perceptual, processing strategy. Interestingly, this effect has been shown to reverse for emotionally arousing materials, such that perceptual processing enhances memory for emotional information or events. The current fMRI study investigated the neural mechanisms of this effect by testing how neural activations during emotional memory retrieval are influenced by the prior encoding strategy. Participants incidentally encoded emotional and neutral pictures under instructions to attend to either semantic or perceptual properties of each picture. Recognition memory was tested 2 days later. fMRI analyses yielded three main findings. First, right amygdalar activity associated with emotional memory strength was enhanced by prior perceptual processing. Second, prior perceptual processing of emotional pictures produced a stronger effect on recollection- than familiarity-related activations in the right amygdala and left hippocampus. Finally, prior perceptual processing enhanced amygdalar connectivity with regions strongly associated with retrieval success, including hippocampal/parahippocampal regions, visual cortex, and ventral parietal cortex. Taken together, the results specify how encoding orientations yield alterations in brain systems that retrieve emotional memories.

  6. Biomedical information retrieval across languages.

    PubMed

    Daumke, Philipp; Markü, Kornél; Poprat, Michael; Schulz, Stefan; Klar, Rüdiger

    2007-06-01

    This work presents a new dictionary-based approach to biomedical cross-language information retrieval (CLIR) that addresses many of the general and domain-specific challenges in current CLIR research. Our method is based on a multilingual lexicon that was generated partly manually and partly automatically, and currently covers six European languages. It contains morphologically meaningful word fragments, termed subwords. Using subwords instead of entire words significantly reduces the number of lexical entries necessary to sufficiently cover a specific language and domain. Mediation between queries and documents is based on these subwords as well as on lists of word-n-grams that are generated from large monolingual corpora and constitute possible translation units. The translations are then sent to a standard Internet search engine. This process makes our approach an effective tool for searching the biomedical content of the World Wide Web in different languages. We evaluate this approach using the OHSUMED corpus, a large medical document collection, within a cross-language retrieval setting.

  7. Query by image example: The CANDID approach

    SciTech Connect

    Kelly, P.M.; Cannon, M.; Hush, D.R.

    1995-02-01

    CANDID (Comparison Algorithm for Navigating Digital Image Databases) was developed to enable content-based retrieval of digital imagery from large databases using a query-by-example methodology. A user provides an example image to the system, and images in the database that are similar to that example are retrieved. The development of CANDID was inspired by the N-gram approach to document fingerprinting, where a ``global signature`` is computed for every document in a database and these signatures are compared to one another to determine the similarity between any two documents. CANDID computes a global signature for every image in a database, where the signature is derived from various image features such as localized texture, shape, or color information. A distance between probability density functions of feature vectors is then used to compare signatures. In this paper, the authors present CANDID and highlight two results from their current research: subtracting a ``background`` signature from every signature in a database in an attempt to improve system performance when using inner-product similarity measures, and visualizing the contribution of individual pixels in the matching process. These ideas are applicable to any histogram-based comparison technique.

  8. Feature representation and compression for content-based retrieval

    NASA Astrophysics Data System (ADS)

    Xie, Hua; Ortega, Antonio

    2000-12-01

    In semantic content-based image/video browsing and navigation systems, efficient mechanisms to represent and manage a large collection of digital images/videos are needed. Traditional keyword-based indexing describes the content of multimedia data through annotations such as text or keywords extracted manually by the user from a controlled vocabulary. This textual indexing technique lacks the flexibility of satisfying various kinds of queries requested by database users and also requires huge amount of work for updating the information. Current content-based retrieval systems often extract a set of features such as color, texture, shape motion, speed, and position from the raw multimedia data automatically and store them as content descriptors. This content-based metadata differs from text-based metadata in that it supports wider varieties of queries and can be extracted automatically, thus providing a promising approach for efficient database access and management. When the raw data volume grows very large, explicitly extracting the content-information and storing it as metadata along with the images will improve querying performance since metadata requires much less storage than the raw image data and thus will be easier to manipulate. In this paper we maintain that storing metadata together with images will enable effective information management and efficient remote query. We also show, using a texture classification example, that this side information can be compressed while guaranteeing that the desired query accuracy is satisfied. We argue that the compact representation of the image contents not only reduces significantly the storage and transmission rate requirement, but also facilitates certain types of queries. Algorithms are developed for optimized compression of this texture feature metadata given that the goal is to maximize the classification performance for a given rate budget.

  9. Retrieval effects on ventilation and cooling requirements for a nuclear waste repository

    SciTech Connect

    Hambley, D.F.

    1985-01-01

    The Nuclear Waste Policy Act of 1982 (Public Law 97-425) and the regulations promulgated in Title 10, Part 60 of the Code of Federal Regulations (10CFR60) by the US Nuclear Regulatory Commission (NRC) for an underground repository for spent fuel and high level nuclear waste (HLW) require that it is possible to retrieve waste, for whatever reason, from such a facility for a period of 50 years from initial storage or until the completion of the performance confirmation period, whichever comes first. This paper considers the effects that the retrievability option mandates on ventilation and cooling systems required for normal repository operations. An example is given for a hypothetical repository in salt. 18 refs., 1 tab.

  10. The design and implementation of image query system based on color feature

    NASA Astrophysics Data System (ADS)

    Yao, Xu-Dong; Jia, Da-Chun; Li, Lin

    2013-07-01

    ASP.NET technology was used to construct the B/S mode image query system. The theory and technology of database design, color feature extraction from image, index and retrieval in the construction of the image repository were researched. The campus LAN and WAN environment were used to test the system. From the test results, the needs of user queries about related resources were achieved by system architecture design.

  11. Acute stress does not affect the impairing effect of chronic stress on memory retrieval

    PubMed Central

    Ozbaki, Jamile; Goudarzi, Iran; Salmani, Mahmoud Elahdadi; Rashidy-Pour, Ali

    2016-01-01

    Objective(s): Due to the prevalence and pervasiveness of stress in modern life and exposure to both chronic and acute stresses, it is not clear whether prior exposure to chronic stress can influence the impairing effects of acute stress on memory retrieval. This issue was tested in this study. Materials and Methods: Adult male Wistar rats were randomly assigned to the following groups: control, acute, chronic, and chronic + acute stress groups. The rats were trained with six trials per day for 6 consecutive days in the water maze. Following training, the rats were either kept in control conditions or exposed to chronic stress in a restrainer 6 hr/day for 21 days. On day 22, a probe test was done to measure memory retention. Time spent in target and opposite areas, platform location latency, and proximity were used as indices of memory retention. To induce acute stress, 30 min before the probe test, animals received a mild footshock. Results: Stressed animals spent significantly less time in the target quadrant and more time in the opposite quadrant than control animals. Moreover, the stressed animals showed significantly increased platform location latency and proximity as compared with control animals. No significant differences were found in these measures among stress exposure groups. Finally, both chronic and acute stress significantly increased corticosterone levels. Conclusion: Our results indicate that both chronic and acute stress impair memory retrieval similarly. Additionally, the impairing effects of chronic stress on memory retrieval were not influenced by acute stress. PMID:27635201

  12. Differential Effects of Parkinson's Disease and Dopamine Replacement on Memory Encoding and Retrieval

    PubMed Central

    MacDonald, Alex A.; Seergobin, Ken N.; Owen, Adrian M.; Tamjeedi, Ruzbeh; Monchi, Oury; Ganjavi, Hooman; MacDonald, Penny A.

    2013-01-01

    Increasingly memory deficits are recognized in Parkinson's disease (PD). In PD, the dopamine-producing cells of the substantia nigra (SN) are significantly degenerated whereas those in the ventral tegmental area (VTA) are relatively spared. Dopamine-replacement medication improves cognitive processes that implicate the SN-innervated dorsal striatum but is thought to impair those that depend upon the VTA-supplied ventral striatum, limbic and prefrontal cortices. Our aim was to examine memory encoding and retrieval in PD and how they are affected by dopamine replacement. Twenty-nine PD patients performed the Rey Auditory Verbal Learning Test (RAVLT) and a non-verbal analogue, the Aggie Figures Learning Test (AFLT), both on and off dopaminergic medications. Twenty-seven, age-matched controls also performed these memory tests twice and their data were analyzed to correspond to the ON-OFF order of the PD patients to whom they were matched. We contrasted measures that emphasized with those that accentuated retrieval and investigated the effect of PD and dopamine-replacement on these processes separately. For PD patients relative to controls, encoding performance was normal in the off state and was impaired on dopaminergic medication. Retrieval was impaired off medication and improved by dopamine repletion. This pattern of findings suggests that VTA-innervated brain regions such as ventral striatum, limbic and prefrontal cortices are implicated in encoding, whereas the SN-supplied dorsal striatum mediates retrieval. Understanding this pattern of spared functions and deficits in PD, and the effect of dopamine replacement on these distinct memory processes, should prompt closer scrutiny of patients' cognitive complaints to inform titration of dopamine replacement dosages along with motor symptoms. PMID:24086309

  13. Differential effects of Parkinson's disease and dopamine replacement on memory encoding and retrieval.

    PubMed

    MacDonald, Alex A; Seergobin, Ken N; Owen, Adrian M; Tamjeedi, Ruzbeh; Monchi, Oury; Ganjavi, Hooman; MacDonald, Penny A

    2013-01-01

    Increasingly memory deficits are recognized in Parkinson's disease (PD). In PD, the dopamine-producing cells of the substantia nigra (SN) are significantly degenerated whereas those in the ventral tegmental area (VTA) are relatively spared. Dopamine-replacement medication improves cognitive processes that implicate the SN-innervated dorsal striatum but is thought to impair those that depend upon the VTA-supplied ventral striatum, limbic and prefrontal cortices. Our aim was to examine memory encoding and retrieval in PD and how they are affected by dopamine replacement. Twenty-nine PD patients performed the Rey Auditory Verbal Learning Test (RAVLT) and a non-verbal analogue, the Aggie Figures Learning Test (AFLT), both on and off dopaminergic medications. Twenty-seven, age-matched controls also performed these memory tests twice and their data were analyzed to correspond to the ON-OFF order of the PD patients to whom they were matched. We contrasted measures that emphasized with those that accentuated retrieval and investigated the effect of PD and dopamine-replacement on these processes separately. For PD patients relative to controls, encoding performance was normal in the off state and was impaired on dopaminergic medication. Retrieval was impaired off medication and improved by dopamine repletion. This pattern of findings suggests that VTA-innervated brain regions such as ventral striatum, limbic and prefrontal cortices are implicated in encoding, whereas the SN-supplied dorsal striatum mediates retrieval. Understanding this pattern of spared functions and deficits in PD, and the effect of dopamine replacement on these distinct memory processes, should prompt closer scrutiny of patients' cognitive complaints to inform titration of dopamine replacement dosages along with motor symptoms.

  14. An Examination of the Impact of Drizzle Drops on Satellite-Retrieved Effective Particle Sizes

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Arduini, Robert F.; Young, David F.; Ayers, J, Kirk; Albrecht, Bruce A.; Sharon, Tarah; Stevens, Bjorn

    2004-01-01

    In general, cloud effective droplet radii are remotely sensed in the near-infrared using the assumption of a monomodal droplet size distribution. It has been observed in many instances, especially in relatively pristine marine environments, that cloud effective droplet radii derived from satellite data often exceed 15 m or more. Comparisons of remotely sensed and in situ retrievals indicate that the former often overestimates the latter in clouds with drizzle-size droplets. To gain a better understanding of this discrepancy, this paper performs a theoretical and empirical evaluation of the impact of drizzle drops on the derived effective radius.

  15. Inactivation of the dorsal hippocampus or the medial prefrontal cortex impairs retrieval but has differential effect on spatial memory reconsolidation.

    PubMed

    Rossato, Janine I; Köhler, Cristiano A; Radiske, Andressa; Bevilaqua, Lia R M; Cammarota, Martín

    2015-11-01

    Active memories can incorporate new information through reconsolidation. However, the notion that memory retrieval is necessary for reconsolidation has been recently challenged. Non-reinforced retrieval induces hippocampus and medial prefrontal cortex (mPFC)-dependent reconsolidation of spatial memory in the Morris water maze (MWM). We found that the effect of protein synthesis inhibition on this process is abolished when retrieval of the learned spatial preference is hindered through mPFC inactivation but not when it is blocked by deactivation of dorsal CA1. Our results do not fully agree with the hypothesis that retrieval is unneeded for reconsolidation. Instead, they support the idea that a hierarchic interaction between the hippocampus and the mPFC controls spatial memory in the MWM, and indicate that this cortex is sufficient to retrieve the information essential to reconsolidate the spatial memory trace, even when the hippocampus is inactivated.

  16. Consistent Query Answering of Conjunctive Queries under Primary Key Constraints

    ERIC Educational Resources Information Center

    Pema, Enela

    2014-01-01

    An inconsistent database is a database that violates one or more of its integrity constraints. In reality, violations of integrity constraints arise frequently under several different circumstances. Inconsistent databases have long posed the challenge to develop suitable tools for meaningful query answering. A principled approach for querying…

  17. Consistent Query Answering of Conjunctive Queries under Primary Key Constraints

    ERIC Educational Resources Information Center

    Pema, Enela

    2014-01-01

    An inconsistent database is a database that violates one or more of its integrity constraints. In reality, violations of integrity constraints arise frequently under several different circumstances. Inconsistent databases have long posed the challenge to develop suitable tools for meaningful query answering. A principled approach for querying…

  18. A similarity learning approach to content-based image retrieval: application to digital mammography.

    PubMed

    El-Naqa, Issam; Yang, Yongyi; Galatsanos, Nikolas P; Nishikawa, Robert M; Wernick, Miles N

    2004-10-01

    In this paper, we describe an approach to content-based retrieval of medical images from a database, and provide a preliminary demonstration of our approach as applied to retrieval of digital mammograms. Content-based image retrieval (CBIR) refers to the retrieval of images from a database using information derived from the images themselves, rather than solely from accompanying text indices. In the medical-imaging context, the ultimate aim of CBIR is to provide radiologists with a diagnostic aid in the form of a display of relevant past cases, along with proven pathology and other suitable information. CBIR may also be useful as a training tool for medical students and residents. The goal of information retrieval is to recall from a database information that is relevant to the user's query. The most challenging aspect of CBIR is the definition of relevance (similarity), which is used to guide the retrieval machine. In this paper, we pursue a new approach, in which similarity is learned from training examples provided by human observers. Specifically, we explore the use of neural networks and support vector machines to predict the user's notion of similarity. Within this framework we propose using a hierarchal learning approach, which consists of a cascade of a binary classifier and a regression module to optimize retrieval effectiveness and efficiency. We also explore how to incorporate online human interaction to achieve relevance feedback in this learning framework. Our experiments are based on a database consisting of 76 mammograms, all of which contain clustered microcalcifications (MCs). Our goal is to retrieve mammogram images containing similar MC clusters to that in a query. The performance of the retrieval system is evaluated using precision-recall curves computed using a cross-validation procedure. Our experimental results demonstrate that: 1) the learning framework can accurately predict the perceptual similarity reported by human observers, thereby

  19. Skin image retrieval using Gabor wavelet texture feature.

    PubMed

    Ou, X; Pan, W; Zhang, X; Xiao, P

    2016-12-01

    Skin imaging plays a key role in many clinical studies. We have used many skin imaging techniques, including the recently developed capacitive contact skin imaging based on fingerprint sensors. The aim of this study was to develop an effective skin image retrieval technique using Gabor wavelet transform, which can be used on different types of skin images, but with a special focus on skin capacitive contact images. Content-based image retrieval (CBIR) is a useful technology to retrieve stored images from database by supplying query images. In a typical CBIR, images are retrieved based on colour, shape, texture, etc. In this study, texture feature is used for retrieving skin images, and Gabor wavelet transform is used for texture feature description and extraction. The results show that the Gabor wavelet texture features can work efficiently on different types of skin images. Although Gabor wavelet transform is slower compared with other image retrieval techniques, such as principal component analysis (PCA) and grey-level co-occurrence matrix (GLCM), Gabor wavelet transform is the best for retrieving skin capacitive contact images and facial images with different orientations. Gabor wavelet transform can also work well on facial images with different expressions and skin cancer/disease images. We have developed an effective skin image retrieval method based on Gabor wavelet transform, that it is useful for retrieving different types of images, namely digital colour face images, digital colour skin cancer and skin disease images, and particularly greyscale skin capacitive contact images. Gabor wavelet transform can also be potentially useful for face recognition (with different orientation and expressions) and skin cancer/disease diagnosis. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  20. Virtual Solar Observatory Distributed Query Construction

    NASA Technical Reports Server (NTRS)

    Gurman, J. B.; Dimitoglou, G.; Bogart, R.; Davey, A.; Hill, F.; Martens, P.

    2003-01-01

    Through a prototype implementation (Tian et al., this meeting) the VSO has already demonstrated the capability of unifying geographically distributed data sources following the Web Services paradigm and utilizing mechanisms such as the Simple Object Access Protocol (SOAP). So far, four participating sites (Stanford, Montana State University, National Solar Observatory and the Solar Data Analysis Center) permit Web-accessible, time-based searches that allow browse access to a number of diverse data sets. Our latest work includes the extension of the simple, time-based queries to include numerous other searchable observation parameters. For VSO users, this extended functionality enables more refined searches. For the VSO, it is a proof of concept that more complex, distributed queries can be effectively constructed and that results from heterogeneous, remote sources can be synthesized and presented to users as a single, virtual data product.

  1. Virtual Solar Observatory Distributed Query Construction

    NASA Technical Reports Server (NTRS)

    Gurman, J. B.; Dimitoglou, G.; Bogart, R.; Davey, A.; Hill, F.; Martens, P.

    2003-01-01

    Through a prototype implementation (Tian et al., this meeting) the VSO has already demonstrated the capability of unifying geographically distributed data sources following the Web Services paradigm and utilizing mechanisms such as the Simple Object Access Protocol (SOAP). So far, four participating sites (Stanford, Montana State University, National Solar Observatory and the Solar Data Analysis Center) permit Web-accessible, time-based searches that allow browse access to a number of diverse data sets. Our latest work includes the extension of the simple, time-based queries to include numerous other searchable observation parameters. For VSO users, this extended functionality enables more refined searches. For the VSO, it is a proof of concept that more complex, distributed queries can be effectively constructed and that results from heterogeneous, remote sources can be synthesized and presented to users as a single, virtual data product.

  2. Virtual Solar Observatory Distributed Query Construction

    NASA Astrophysics Data System (ADS)

    Gurman, J. B.; Dimitoglou, G.; Bigart, R. S.; Davey, A. R.; Hill, F.; Martens, P. C.; Tian, K. Q.; Wampler, S.

    2003-12-01

    Through a prototype implementation (Tian et al., this meeting) the VSO has already demonstrated the capability of unifying geographically distributed data sources following the Web Services paradigm and utilizing mechanisms such as the Simple Object Access Protocol (SOAP). So far, four participating sites (Stanford, Montana State University, National Solar Observatory and the Solar Data Analysis Center) permit Web-accessible, time-based searches that allow browse access to a number of diverse data sets. Our latest work includes the extension of the simple, time-based queries to include numerous other searchable observation parameters. For VSO users, this extended functionality enables more refined searches. For the VSO, it is a proof of concept that more complex, distributed queries can be effectively constructed and that results from heterogeneous, remote sources can be synthesized and presented to users as a single, virtual data product.

  3. Design and evaluation of a temporal, graph-based language for querying collections of patient histories.

    PubMed

    Edsberg, Ole; Nordbø, Stein Jakob; Vinnes, Erik; Nytrø, Øystein

    2007-01-01

    Giving clinicians and researchers the ability to easily retrieve and explore relevant fragments of patient histories would greatly facilitate quality assurance, patient followup and research on patient treatment processes. Established database query languages are inconvenient for such exploration, and may also be too complex for users with limited backgrounds in informatics. We believe that understandability can be increased in return for a sacrifice of some of the power of expression found in general query languages. In order to design a specialized query language, we have collected and synthesized a tentative list of requirements. Based on these requirements, we have designed and implemented Practice Explorer, a prototype for visual query of collections of patient histories, and evaluated the understandability of its query language by testing with medical students. The results indicate that parts of the language are intuitive enough for users to understand without demonstrations, examples, feedback or assistance. They also provide some lessons for future work in this area.

  4. The hippocampus, medial prefrontal cortex, and selective memory retrieval: evidence from a rodent model of the retrieval-induced forgetting effect.

    PubMed

    Wu, Jade Q; Peters, Greg J; Rittner, Pedro; Cleland, Thomas A; Smith, David M

    2014-09-01

    Inhibition is an important component of many cognitive functions, including memory. For example, the retrieval-induced forgetting (RIF) effect occurs when extra practice with some items from a study list inhibits the retrieval of the nonpracticed items relative to a baseline condition that does not involve extra practice. Although counterintuitive, the RIF phenomenon may be important for resolving interference by inhibiting potentially competing retrieval targets. Neuroimaging studies suggest that the hippocampus and prefrontal cortex are involved in the RIF effect, but controlled lesion studies have not yet been performed. We developed a rodent model of the RIF training procedure and trained control rats and rats with temporary inactivation of the hippocampus or medial prefrontal cortex (mPFC). Rats were trained on a list of odor cues, presented in cups of digging medium with a buried reward, followed by additional practice trials with a subset of the cues. We then tested the rats' memories for the cues and their association with reward by presenting them with unbaited cups containing the test odorants and measuring how long they persisted in digging. Control rats exhibited a robust RIF effect in which memory for the nonpracticed odors was significantly inhibited. Thus, extra practice with some odor cues inhibited memory for the others, relative to a baseline condition that involved an identical amount of training. Inactivation of either the hippocampus or the mPFC blocked the RIF effect. We also constructed a computational model of a representational learning circuit to simulate the RIF effect. We show in this model that "sideband suppression" of similar memory representations can reproduce the RIF effect and that alteration of the suppression parameters and learning rate can reproduce the lesion effects seen in our rats. Our results suggest that the RIF effect is widespread and that inhibitory processes are an important feature of memory function. © 2014 Wiley

  5. The hippocampus, medial prefrontal cortex and selective memory retrieval: Evidence from a rodent model of the retrieval-induced forgetting effect

    PubMed Central

    Wu, Jade Q.; Peters, Greg J.; Rittner, Pedro; Cleland, Thomas A.; Smith, David M.

    2014-01-01

    Inhibition is an important component of many cognitive functions, including memory. For example, the retrieval-induced forgetting (RIF) effect occurs when extra practice with some items from a study list inhibits the retrieval of the non-practiced items relative to a baseline condition that does not involve extra practice. Though counterintuitive, the RIF phenomenon may be important for resolving interference by inhibiting potentially competing retrieval targets. Neuroimaging studies suggest that the hippocampus and prefrontal cortex (PFC) are involved in the RIF effect, but controlled lesion studies have not yet been performed. We developed a rodent model of the RIF training procedure and trained control rats and rats with temporary inactivation of the hippocampus or mPFC. Rats were trained on a list of odor cues, presented in cups of digging medium with a buried reward, followed by additional practice trials with a subset of the cues. We then tested the rats’ memories for the cues and their association with reward by presenting them with unbaited cups containing the test odorants and measuring how long they persisted in digging. Control rats exhibited a robust RIF effect in which memory for the non-practiced odors was significantly inhibited. Thus, extra practice with some odor cues inhibited memory for the others, relative to a baseline condition that involved an identical amount of training. Inactivation of either the hippocampus or the mPFC blocked the RIF effect. We also constructed a computational model of a representational learning circuit to simulate the RIF effect. We show in this model that ‘sideband suppression’ of similar memory representations can reproduce the RIF effect and that alteration of the suppression parameters and learning rate can reproduce the lesion effects seen in our rats. Our results suggest that the RIF effect is widespread and that inhibitory processes are an important feature of memory function. PMID:24753146

  6. Diagnostic test systematic reviews: bibliographic search filters ("Clinical Queries") for diagnostic accuracy studies perform well.

    PubMed

    Kastner, Monika; Wilczynski, Nancy L; McKibbon, Ann K; Garg, Amit X; Haynes, R Brian

    2009-09-01

    Systematic reviews of health care topics are valuable summaries of all pertinent studies on focused questions. However, finding all relevant primary studies for systematic reviews remains challenging. To determine the performance of the Clinical Queries sensitive search filter for diagnostic accuracy studies for retrieving studies for systematic reviews. We compared the yield of the sensitive Clinical Queries diagnosis search filter for MEDLINE and EMBASE to retrieve studies in diagnostic accuracy systematic reviews reported in ACP Journal Club in 2006. Twelve of 22 diagnostic accuracy reviews (452 included studies) met the inclusion criteria. After excluding 11 studies not in MEDLINE or EMBASE, 95% of articles (417 of 441) were captured by the sensitive Clinical Queries diagnosis search filter (MEDLINE and EMBASE combined). Of 24 studies not retrieved by the filter, 22 were not diagnostic accuracy studies. Reanalysis of the Clinical Queries filter without these 22 nondiagnosis articles increased its performance to 99% (417 of 419). We found no substantive impact of the two articles missed by the Clinical Queries filter on the conclusions of the systematic reviews in which they were cited. The sensitive Clinical Queries diagnostic search filter captured 99% of articles and 100% of substantive articles indexed in MEDLINE and EMBASE in diagnostic accuracy systematic reviews.

  7. Contrasting Effects of Errorless Naming Treatment and Gestural Facilitation for Word Retrieval in Aphasia

    PubMed Central

    Raymer, Anastasia M.; McHose, Beth; Smith, Kimberly G.; Iman, Lisa; Ambrose, Alexis; Casselton, Colleen

    2011-01-01

    Purpose We compared the effects of two treatments for aphasic word retrieval impairments, errorless naming treatment (ENT) and gestural facilitation of naming (GES), within the same individuals, anticipating that the use of gesture would enhance the effect of treatment over errorless treatment alone. In addition to picture naming, we evaluated results for other outcome measures that were largely untested in earlier ENT studies. Methods In a single participant crossover treatment design, we examined the effects of ENT and GES in eight individuals with stroke-induced aphasia and word retrieval impairments (three semantic anomia, five phonologic anomia) in counterbalanced phases across participants. We evaluated effects of the two treatments for a daily picture naming/gesture production probe measure and in standardized aphasia tests and communication rating scales administered across phases of the experiment. Results Both treatments led to improvements in naming of trained words (small-to-large effect sizes) in individuals with semantic and phonologic anomia. Small generalized naming improvements were noted for three individuals with phonologic anomia. GES improved use of corresponding gestures for trained words (large effect sizes). Results were largely maintained at one month post treatment completion. Increases in scores on standardized aphasia testing also occurred for both ENT and GES training. Discussion Both ENT and GES led to improvements in naming measures, with no clear difference between treatments. Increased use of gestures following GES providing a potential compensatory means of communication for those who did not improve verbal skills. Both treatments are considered to be effective methods to promote recovery of word retrieval and verbal production skills in individuals with aphasia. PMID:22047100

  8. BioFed: federated query processing over life sciences linked open data.

    PubMed

    Hasnain, Ali; Mehmood, Qaiser; Sana E Zainab, Syeda; Saleem, Muhammad; Warren, Claude; Zehra, Durre; Decker, Stefan; Rebholz-Schuhmann, Dietrich

    2017-03-15

    Biomedical data, e.g. from knowledge bases and ontologies, is increasingly made available following open linked data principles, at best as RDF triple data. This is a necessary step towards unified access to biological data sets, but this still requires solutions to query multiple endpoints for their heterogeneous data to eventually retrieve all the meaningful information. Suggested solutions are based on query federation approaches, which require the submission of SPARQL queries to endpoints. Due to the size and complexity of available data, these solutions have to be optimised for efficient retrieval times and for users in life sciences research. Last but not least, over time, the reliability of data resources in terms of access and quality have to be monitored. Our solution (BioFed) federates data over 130 SPARQL endpoints in life sciences and tailors query submission according to the provenance information. BioFed has been evaluated against the state of the art solution FedX and forms an important benchmark for the life science domain. The efficient cataloguing approach of the federated query processing system 'BioFed', the triple pattern wise source selection and the semantic source normalisation forms the core to our solution. It gathers and integrates data from newly identified public endpoints for federated access. Basic provenance information is linked to the retrieved data. Last but not least, BioFed makes use of the latest SPARQL standard (i.e., 1.1) to leverage the full benefits for query federation. The evaluation is based on 10 simple and 10 complex queries, which address data in 10 major and very popular data sources (e.g., Dugbank, Sider). BioFed is a solution for a single-point-of-access for a large number of SPARQL endpoints providing life science data. It facilitates efficient query generation for data access and provides basic provenance information in combination with the retrieved data. BioFed fully supports SPARQL 1.1 and gives access to the

  9. Retrieval of Emotional Memories

    PubMed Central

    Buchanan, Tony W.

    2008-01-01

    Long-term memories are influenced by the emotion experienced during learning as well as by the emotion experienced during memory retrieval. The present article reviews the literature addressing the effects of emotion on retrieval, focusing on the cognitive and neurological mechanisms that have been revealed. The reviewed research suggests that the amygdala, in combination with the hippocampus and prefrontal cortex, plays an important role in the retrieval of memories for emotional events. The neural regions necessary for online emotional processing also influence emotional memory retrieval, perhaps through the reexperience of emotion during the retrieval process. PMID:17723029

  10. Computation of the Effects of Inhomogeneous Clouds on Retrieval of Remotely Sensed Properties

    NASA Technical Reports Server (NTRS)

    Chambers, Lin H.

    1998-01-01

    Current and future earth observation programs depend on satellite measurements of radiance to retrieve the properties of clouds on a global basis. At present, this retrieval is made assuming that the clouds in the instrument field of view are plane parallel and independent of adjacent pixels. While this assumption is known to be false except in very limited cases, its impact can be evaluated, and if possible corrected, based on emerging theoretical techniques. In this study, the Spherical Harmonic Discrete Ordinate Method (SHDOM, Evans, 1996) has been used to assess the sensitivity of the retrieval to a variety of cloud parameters. SHDOM allows the plane parallel assumption to be relaxed and makes 2D and even 3D radiative solutions practical. A previous study (Chambers et al., 1996) assessed the effect of horizontal inhomogeneity in 45 LANDSAT scenes of boundary layer clouds over ocean. The four scenes studied here represent overcast, broken, scattered and strongly thermally forced cloud fields and are used to perform sensitivity studies to a wider variety of parameters. Comparisons are made at three solar zenith angles (theta (sub 0) = 0, 49, and 63 degrees) to avoid ambiguity in the results due to solar zenith angle.

  11. An effective inversion algorithm for retrieving bimodal aerosol particle size distribution from spectral extinction data

    NASA Astrophysics Data System (ADS)

    He, Zhenzong; Qi, Hong; Yao, Yuchen; Ruan, Liming

    2014-12-01

    The Ant Colony Optimization algorithm based on the probability density function (PDF-ACO) is applied to estimate the bimodal aerosol particle size distribution (PSD). The direct problem is solved by the modified Anomalous Diffraction Approximation (ADA, as an approximation for optically large and soft spheres, i.e., χ≫1 and |m-1|≪1) and the Beer-Lambert law. First, a popular bimodal aerosol PSD and three other bimodal PSDs are retrieved in the dependent model by the multi-wavelength extinction technique. All the results reveal that the PDF-ACO algorithm can be used as an effective technique to investigate the bimodal PSD. Then, the Johnson's SB (J-SB) function and the modified beta (M-β) function are employed as the general distribution function to retrieve the bimodal PSDs under the independent model. Finally, the J-SB and M-β functions are applied to recover actual measurement aerosol PSDs over Beijing and Shanghai obtained from the aerosol robotic network (AERONET). The numerical simulation and experimental results demonstrate that these two general functions, especially the J-SB function, can be used as a versatile distribution function to retrieve the bimodal aerosol PSD when no priori information about the PSD is available.

  12. Information retrieval: an overview of system characteristics.

    PubMed

    Wiesman, F; Hasman, A; van den Herik, H J

    1997-11-01

    The paper gives an overview of characteristics of information retrieval (IR) systems. The characteristics are identified from the descriptions of 23 IR systems. Four IR models are discussed: the Boolean model, the vector model, the probabilistic model and the connectionistic model. Twelve other characteristics of IR models are identified: search intermediary, domain knowledge, relevance feedback, natural language interface, graphical query language, conceptual queries, full-text IR, field searching, fuzzy queries, hypertext integration, machine learning, and ranked output. Finally, the relevance of IR systems for the World Wide Web is established.

  13. Effect of emissivity uncertainty on surface temperature retrieval over urban areas: Investigations based on spectral libraries

    NASA Astrophysics Data System (ADS)

    Chen, Feng; Yang, Song; Su, Z.; Wang, Kai

    2016-04-01

    Land surface emissivity (LSE) is a prerequisite for retrieving land surface temperature (LST) through single channel methods. According to error model, a 0.01 (1%) uncertainty of LSE may result in a 0.5 K error in LST under a moderate condition, while an obvious error (approximately 1 K) is possible under a warmer and less humid situation. Significant emissivity variations are presented among the anthropogenic materials in three spectral libraries, which raise a critical question that whether urban LSE can be estimated accurately to meet the needs for LST retrieval. Methods widely used for urban LSE estimation are investigated, including the classification-based method, the spectral-index based method, and the linear spectral mixture model (LSMM). Results indicate that the classification-based method may not be effectively applicable for urban LSE estimation, due mainly to the insignificant relation between the short-wave multispectral reflectance and the long-wave thermal emissivity shown by the spectra. Compared with the classification-based method, the LSMM shows relatively more accurate predictions, whereas, the performance of the LSMM largely depends on the determination of endmembers. Obvious uncertainties in LSE estimation likely appear if endmembers are determined improperly. Increasing the spectra for endmembers is a practical and beneficial means for LSMM when there is not a priori knowledge, which emphasizes the necessity of building a comprehensive spectral library of urban materials. Furthermore, the LST retrieval from a single channel of Landsat 8 is more challenging as compared with the retrieval from the channels of its predecessors-Landsat 4/5/7.

  14. A Unified Maximum Likelihood Approach to Document Retrieval.

    ERIC Educational Resources Information Center

    Bodoff, David; Enache, Daniel; Kambil, Ajit; Simon, Gary; Yukhimets, Alex

    2001-01-01

    Addresses the query- versus document-oriented dichotomy in information retrieval. Introduces a maximum likelihood approach to utilizing feedback data that can be used to construct a concrete object function that estimates both document and query parameters in accordance with all available feedback data. (AEF)

  15. Information Storage and Retrieval, Scientific Report No. ISR-15.

    ERIC Educational Resources Information Center

    Salton, Gerard

    Several algorithms were investigated which would allow a user to interact with an automatic document retrieval system by requesting relevance judgments on selected sets of documents. Two viewpoints were taken in evaluation. One measured the movement of queries toward the optimum query as defined by Rocchio; the other measured the retrieval…

  16. Document Retrieval Using a Serial Bit String Search.

    ERIC Educational Resources Information Center

    Harding, Alan F.; And Others

    1983-01-01

    The experimental best match information retrieval system described is based on serial file organization. Documents and queries are characterized by fixed length bit strings (generated by automatic and manual methods) and character-by-character term match is preceeded by bit string search to eliminate documents which cannot satisfy query.…

  17. The Use of Automatic Relevance Feedback in Boolean Retrieval Systems.

    ERIC Educational Resources Information Center

    Dillon, Martin; Desper, James

    1980-01-01

    Describes a technique for automatic reformulation of Boolean queries which compares favorably with feedback as employed in a SMART system. Using patron relevance judgments, prevalence measures reflecting term distribution in relevant and nonrelevant documents are derived to guide the construction of a Boolean query for a subsequent retrieval.…

  18. Querying Large Biological Network Datasets

    ERIC Educational Resources Information Center

    Gulsoy, Gunhan

    2013-01-01

    New experimental methods has resulted in increasing amount of genetic interaction data to be generated every day. Biological networks are used to store genetic interaction data gathered. Increasing amount of data available requires fast large scale analysis methods. Therefore, we address the problem of querying large biological network datasets.…

  19. Image Querying by Image Professionals.

    ERIC Educational Resources Information Center

    Jorgensen, Corinne; Jorgensen, Peter

    2003-01-01

    Reports the analysis of search logs from a commercial image provider over a one-month period and discusses results in relation to previous findings. Analyzes image searches, image queries composing the search, user search modification strategies, results returned, and user browsing of results. (Author/AEF)

  20. Querying Large Biological Network Datasets

    ERIC Educational Resources Information Center

    Gulsoy, Gunhan

    2013-01-01

    New experimental methods has resulted in increasing amount of genetic interaction data to be generated every day. Biological networks are used to store genetic interaction data gathered. Increasing amount of data available requires fast large scale analysis methods. Therefore, we address the problem of querying large biological network datasets.…

  1. Neural correlates of episodic retrieval: an fMRI study of the part-list cueing effect.

    PubMed

    Crescentini, Cristiano; Shallice, Tim; Del Missier, Fabio; Macaluso, Emiliano

    2010-04-01

    Episodic retrieval is supported by multiple forms of cognitive control that depend on prefrontal cortex. However, within prefrontal cortex, the regional specificity for different control processes is still largely underspecified. Here we used fMRI to investigate the processes involved in part-list cueing, a phenomenon entailing the reduction of memory performance when some of the "to-be-remembered items" are presented during retrieval. Retrieval inhibition and strategy disruption have been proposed as possible underlying causes of this surprising effect. Critically, different encoding conditions can dissociate these two hypotheses, as this is thought to have a different impact on strategy-related versus inhibition-related processes. Accordingly, we compared part-list versus no part-list retrieval conditions, following high versus low associative encoding conditions. This revealed activation of the left frontopolar and right dorsolateral prefrontal cortex in conditions of part-list cueing retrieval, but only following low associative encoding. These results are consistent with the inhibitory or interference resolution accounts of part-list cueing, suggesting a critical role of between-items competition and high monitoring demands at retrieval. In addition, we also examined brain activation during the encoding phase, specifying further possible anatomo-functional links between encoding and retrieval processes. The results suggest that different encoding conditions induce distinct patterns of activation at retrieval, corroborating the idea that they promote the adoption of different retrieval strategies. The implications of the results are discussed in relation to the cognitive mechanisms of inhibition, interference resolution, and encoding/retrieval strategies for episodic memory. Copyright 2009 Elsevier Inc. All rights reserved.

  2. Metacognition of the testing effect: Guiding learners to predict the benefits of retrieval

    PubMed Central

    Tullis, Jonathan G.; Finley, Jason R.; Benjamin, Aaron S.

    2012-01-01

    If the mnemonic benefits of testing are to be widely realized in real-world learning circumstances, people must appreciate the value of testing and choose to utilize testing during self-guided learning. Yet metacognitive judgments do not appear to reflect the enhancement provided by testing (Karpicke & Roediger, 2008). In this paper, we show that under judicious conditions learners can indeed reveal an understanding of the beneficial effects of testing as well as the interaction of that effect with delay (Experiment 1). In that experiment, subjects made judgments of learning (JOLs) for previously studied or previously tested items in either a cue-only or cue-target context, and either immediately or after a one-day delay. When subjects made judgments in a cue-only context, their JOLs accurately reflected the effects of testing, both immediately and at a delay. To evaluate the potential of exposure to such conditions for promoting generalized appreciation of testing effects, three further experiments elicited global predictions about re-studied and tested items across two study/test cycles (Experiments 2, 3, and 4). The results indicated that learners’ global naïve metacognitive beliefs increasingly reflect the beneficial effects of testing when learners experience these benefits with increasing external support. If queried under facilitative circumstances, learners appreciate the mnemonic enhancement that testing provides on both an item-by-item and global basis, but generalize that knowledge to future learning only with considerable guidance. PMID:23242770

  3. Metacognition of the testing effect: guiding learners to predict the benefits of retrieval.

    PubMed

    Tullis, Jonathan G; Finley, Jason R; Benjamin, Aaron S

    2013-04-01

    If the mnemonic benefits of testing are to be widely realized in real-world learning circumstances, people must appreciate the value of testing and choose to utilize testing during self-guided learning. Yet metacognitive judgments do not appear to reflect the enhancement provided by testing Karpicke & Roediger (Science 319:966-968, 2008). In this article, we show that under judicious conditions, learners can indeed reveal an understanding of the beneficial effects of testing, as well as the interaction of that effect with delay (experiment 1). In that experiment, subjects made judgments of learning (JOLs) for previously studied or previously tested items in either a cue-only or a cue-target context, and either immediately or after a 1-day delay. When subjects made judgments in a cue-only context, their JOLs accurately reflected the effects of testing, both immediately and at a delay. To evaluate the potential of exposure to such conditions for promoting generalized appreciation of testing effects, three further experiments elicited global predictions about restudied and tested items across two study/test cycles (experiments 2, 3, and 4). The results indicated that learners' global naïve metacognitive beliefs increasingly reflect the beneficial effects of testing when learners experience these benefits with increasing external support. If queried under facilitative circumstances, learners appreciate the mnemonic enhancement that testing provides on both an item-by-item and global basis but generalize that knowledge to future learning only with considerable guidance.

  4. Automatic building information model query generation

    DOE PAGES

    Jiang, Yufei; Yu, Nan; Ming, Jiang; ...

    2015-12-01

    Energy efficient building design and construction calls for extensive collaboration between different subfields of the Architecture, Engineering and Construction (AEC) community. Performing building design and construction engineering raises challenges on data integration and software interoperability. Using Building Information Modeling (BIM) data hub to host and integrate building models is a promising solution to address those challenges, which can ease building design information management. However, the partial model query mechanism of current BIM data hub collaboration model has several limitations, which prevents designers and engineers to take advantage of BIM. To address this problem, we propose a general and effective approachmore » to generate query code based on a Model View Definition (MVD). This approach is demonstrated through a software prototype called QueryGenerator. In conclusion, by demonstrating a case study using multi-zone air flow analysis, we show how our approach and tool can help domain experts to use BIM to drive building design with less labour and lower overhead cost.« less

  5. Mechanisms behind the testing effect: an empirical investigation of retrieval practice in meaningful learning

    PubMed Central

    Endres, Tino; Renkl, Alexander

    2015-01-01

    The testing effect—more learning by testing as compared to restudying—is a well-established finding. A typical testing procedure in the context of meaningful learning comprises a recall task after an initial study phase. Different theories refer to different mechanisms when explaining the positive effects of such recall tasks. In the context of learning from expository texts, we tested three mechanisms as suggested by a variety of prominent approaches: the elaborative-retrieval theory, the theory of transfer-appropriate processing, and the unspecific-goal perspective. We experimentally varied the type of testing task (short-answer task vs. free-recall task, both compared to a restudy task) in a within-subject design (N = 47 university students). We replicated the testing effect. We found no evidence for a transfer-appropriate processing effect or an unspecific-goal effect. The testing effect disappeared when statistically controlling for mental effort. Initially non-tested material was also fostered by testing (spreading activation effect). These findings indicate that testing helps learning when learners must invest substantial mental effort, as suggested by the elaborative retrieval theory. For educational purposes, testing tasks should be assigned that require the learners to invest substantial mental effort. PMID:26257696

  6. Large Catalogue Query Performance in Relational Databases

    NASA Astrophysics Data System (ADS)

    Power, Robert A.

    2007-05-01

    The performance of the mysql and oracle database systems have been compared for a selection of astronomy queries using large catalogues of up to a billion objects. The queries tested are those expected from the astronomy community: general database queries, cone searches, neighbour finding and cross matching. The catalogue preparation, sql query formulation and database performance is presented. Most of the general queries perform adequately when appropriate indexes are present in the database. Each system performs well for cone search queries when the Hierarchical Triangular Mesh spatial index is used. Neighbour finding and cross matching are not well supported in a database environment when compared to software specifically developed to solve these problems.

  7. Using Genome Query Language to uncover genetic variation

    PubMed Central

    Kozanitis, Christos; Heiberg, Andrew; Varghese, George; Bafna, Vineet

    2014-01-01

    Motivation: With high-throughput DNA sequencing costs dropping <$1000 for human genomes, data storage, retrieval and analysis are the major bottlenecks in biological studies. To address the large-data challenges, we advocate a clean separation between the evidence collection and the inference in variant calling. We define and implement a Genome Query Language (GQL) that allows for the rapid collection of evidence needed for calling variants. Results: We provide a number of cases to showcase the use of GQL for complex evidence collection, such as the evidence for large structural variations. Specifically, typical GQL queries can be written in 5–10 lines of high-level code and search large datasets (100 GB) in minutes. We also demonstrate its complementarity with other variant calling tools. Popular variant calling tools can achieve one order of magnitude speed-up by using GQL to retrieve evidence. Finally, we show how GQL can be used to query and compare multiple datasets. By separating the evidence and inference for variant calling, it frees all variant detection tools from the data intensive evidence collection and focuses on statistical inference. Availability: GQL can be downloaded from http://cseweb.ucsd.edu/~ckozanit/gql. Contact: ckozanit@ucsd.edu or vbafna@cs.ucsd.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:23751181

  8. Using Genome Query Language to uncover genetic variation.

    PubMed

    Kozanitis, Christos; Heiberg, Andrew; Varghese, George; Bafna, Vineet

    2014-01-01

    With high-throughput DNA sequencing costs dropping <$1000 for human genomes, data storage, retrieval and analysis are the major bottlenecks in biological studies. To address the large-data challenges, we advocate a clean separation between the evidence collection and the inference in variant calling. We define and implement a Genome Query Language (GQL) that allows for the rapid collection of evidence needed for calling variants. We provide a number of cases to showcase the use of GQL for complex evidence collection, such as the evidence for large structural variations. Specifically, typical GQL queries can be written in 5-10 lines of high-level code and search large datasets (100 GB) in minutes. We also demonstrate its complementarity with other variant calling tools. Popular variant calling tools can achieve one order of magnitude speed-up by using GQL to retrieve evidence. Finally, we show how GQL can be used to query and compare multiple datasets. By separating the evidence and inference for variant calling, it frees all variant detection tools from the data intensive evidence collection and focuses on statistical inference. GQL can be downloaded from http://cseweb.ucsd.edu/~ckozanit/gql.

  9. A Web-Based Data-Querying Tool Based on Ontology-Driven Methodology and Flowchart-Based Model

    PubMed Central

    Ping, Xiao-Ou; Chung, Yufang; Liang, Ja-Der; Yang, Pei-Ming; Huang, Guan-Tarn; Lai, Feipei

    2013-01-01

    Background Because of the increased adoption rate of electronic medical record (EMR) systems, more health care records have been increasingly accumulating in clinical data repositories. Therefore, querying the data stored in these repositories is crucial for retrieving the knowledge from such large volumes of clinical data. Objective The aim of this study is to develop a Web-based approach for enriching the capabilities of the data-querying system along the three following considerations: (1) the interface design used for query formulation, (2) the representation of query results, and (3) the models used for formulating query criteria. Methods The Guideline Interchange Format version 3.5 (GLIF3.5), an ontology-driven clinical guideline representation language, was used for formulating the query tasks based on the GLIF3.5 flowchart in the Protégé environment. The flowchart-based data-querying model (FBDQM) query execution engine was developed and implemented for executing queries and presenting the results through a visual and graphical interface. To examine a broad variety of patient data, the clinical data generator was implemented to automatically generate the clinical data in the repository, and the generated data, thereby, were employed to evaluate the system. The accuracy and time performance of the system for three medical query tasks relevant to liver cancer were evaluated based on the clinical data generator in the experiments with varying numbers of patients. Results In this study, a prototype system was developed to test the feasibility of applying a methodology for building a query execution engine using FBDQMs by formulating query tasks using the existing GLIF. The FBDQM-based query execution engine was used to successfully retrieve the clinical data based on the query tasks formatted using the GLIF3.5 in the experiments with varying numbers of patients. The accuracy of the three queries (ie, “degree of liver damage,” “degree of liver damage

  10. The Use of a Context-Based Information Retrieval Technique

    DTIC Science & Technology

    2009-07-01

    information retrieval. For instance, information retrieval tools must contend with obstacles such as polysemy , which refers to words with multiple...meanings, and synonymy, which is used to describe multiple words with the same meaning. Many of these problems can be minimised when the query is...with the proportion of retrieved items that are relevant. Information retrieval systems aim to maximise both of these measures, and

  11. A fast video clip retrieval algorithm based on VA-file

    NASA Astrophysics Data System (ADS)

    Liu, Fangjie; Dong, DaoGuo; Miao, Xiaoping; Xue, XiangYang

    2003-12-01

    Video clip retrieval is a significant research topic of content-base multimedia retrieval. Generally, video clip retrieval process is carried out as following: (1) segment a video clip into shots; (2) extract a key frame from each shot as its representative; (3) denote every key frame as a feature vector, and thus a video clip can be denoted as a sequence of feature vectors; (4) retrieve match clip by computing the similarity between the feature vector sequence of a query clip and the feature vector sequence of any clip in database. To carry out fast video clip retrieval the index structure is indispensable. According to our literature survey, S2-tree [17] is the one and only index structure having been applied to support video clip retrieval, which combines the characteristics of both X-tree and Suffix-tree and converts the series vectors retrieval to string matching. But S2-tree structure will not be applicable if the feature vector's dimension is beyond 20, because the X-tree itself cannot be used to sustain similarity query effectively when dimensions of vectors are beyond 20. Furthermore, it cannot support flexible similarity definitions between two vector sequences. VA-file represents the vector approximately by compressing the original data and it maintains the original order when representing vectors in a sequence, which is a very valuable merit for vector sequences matching. In this paper, a new video clip similarity model as well as video clip retrieval algorithm based on VA-File are proposed. The experiments show that our algorithm incredibly shortened the retrieval time compared to sequential scanning without index structure.

  12. MODIS Aerosol Optical Depth retrieval over land considering surface BRDF effects

    NASA Astrophysics Data System (ADS)

    Wu, Yerong; de Graaf, Martin; Menenti, Massimo

    2016-04-01

    Aerosols in the atmosphere play an important role in the climate system and human health. Retrieval from satellite data, Aerosol Optical Depth (AOD), one of most important indices of aerosol optical properties, has been extensively investigated. Benefiting from the high resolution at spatial and temporal and the maturity of the aerosol retrieval algorithm, MOderate Resolution Imaging Spectroradiometer (MODIS) Dark Target AOD product has been extensively applied in other scientific research such as climate change and air pollution. The latest product - MODIS Collection 6 Dark Target AOD (C6_DT) has been released. However, the accuracy of C6_DT AOD (global mean ±0.03) over land is still too low for the constraint on radiative forcing in the climate system, where the uncertainty should be reduced to ±0.02. The major uncertainty mainly lies on the underestimation/overestimation of the surface contribution to the Top Of Atmosphere (TOA) radiance since a lambertian surface is assumed in the C6_DT land algorithm. In the real world, it requires considering the heterogeneity of the surface reflection in the radiative transfer process. Based on this, we developed a new algorithm to retrieve AOD by considering surface Bidirectional Reflectance Distribution Function (BRDF) effects. The surface BRDF is much more complicated than isotropic reflection, described as 4 elements: directional-directional, directional-hemispherical, hemispherical-directional and hemispherical-hemispherical reflectance, and coupled into radiative transfer equation to generate an accurate top of atmosphere reflectance. The limited MODIS measurements (three channels available) allow us to retrieve only three parameters, which including AOD, the surface directional-directional reflectance and fine aerosol ratio η. The other three elements of the surface reflectance are expected to be constrained by ancillary data and assumptions or "a priori" information since there are more unknowns than MODIS

  13. VQLM: A visual query language for macromolecular structural databases

    SciTech Connect

    Cohen, D.; Dickinson, B.; Salem, H.

    1994-12-31

    Databases of macromolecular structures allow researchers to identify general principles of molecular behavior. They do this by providing a variety of data obtained under a number of different experimental conditions. Many new tools have been developed recently to aid in exploratory analysis of structural data. However, some queries of interest still require considerable manual filtering of data. In particular, studies attempting to make generalizations about complex arrangements of atoms or building blocks in macro-molecular structures cannot be approached directly with existing tools. Such studies are frequently carried out on only a few structures or else require a labor-intensive process. To address this problem, we have developed a visual language, VQLM (Visual Query Language for Macromolecules). A query is formulated in this language by drawing an abstract picture of sub-structures to be searched for in the database and specifying constraints on the objects in them. To illustrate the usefulness of our language, we show how to encode a number of queries that were found scientifically interesting in the published literature in molecular biology. VQLM relies on VQL, a new database language, as its underlying engine for database retrieval and computation. We believe that VQLM will make macromolecular structural data more accessible to scientists, enabling faster and deeper data analysis.

  14. W-transform method for feature-oriented multiresolution image retrieval

    SciTech Connect

    Kwong, M.K.; Lin, B.

    1995-07-01

    Image database management is important in the development of multimedia technology. Since an enormous amount of digital images is likely to be generated within the next few decades in order to integrate computers, television, VCR, cables, telephone and various imaging devices. Effective image indexing and retrieval systems are urgently needed so that images can be easily organized, searched, transmitted, and presented. Here, the authors present a local-feature-oriented image indexing and retrieval method based on Kwong, and Tang`s W-transform. Multiresolution histogram comparison is an effective method for content-based image indexing and retrieval. However, most recent approaches perform multiresolution analysis for whole images but do not exploit the local features present in the images. Since W-transform is featured by its ability to handle images of arbitrary size, with no periodicity assumptions, it provides a natural tool for analyzing local image features and building indexing systems based on such features. In this approach, the histograms of the local features of images are used in the indexing, system. The system not only can retrieve images that are similar or identical to the query images but also can retrieve images that contain features specified in the query images, even if the retrieved images as a whole might be very different from the query images. The local-feature-oriented method also provides a speed advantage over the global multiresolution histogram comparison method. The feature-oriented approach is expected to be applicable in managing large-scale image systems such as video databases and medical image databases.

  15. SPIRS: A Web-based Image Retrieval System for Large Biomedical Databases

    PubMed Central

    Hsu, William; Antani, Sameer; Long, L. Rodney; Neve, Leif; Thoma, George R.

    2009-01-01

    Purpose With the increasing use of images in disease research, education, and clinical medicine, the need for methods that effectively archive, query, and retrieve these images by their content is underscored. This paper describes the implementation of a Web-based retrieval system called SPIRS (Spine Pathology & Image Retrieval System), which permits exploration of a large biomedical database of digitized spine x-ray images and data from a national health survey using a combination of visual and textual queries. Methods SPIRS is a generalizable framework that consists of four components: a client applet, a gateway, an indexing and retrieval system, and a database of images and associated text data. The prototype system is demonstrated using text and imaging data collected as part of the second U.S. National Health and Nutrition Examination Survey (NHANES II). Users search the image data by providing a sketch of the vertebral outline or selecting an example vertebral image and some relevant text parameters. Pertinent pathology on the image/sketch can be annotated and weighted to indicate importance. Results During the course of development, we explored different algorithms to perform functions such as segmentation, indexing, and retrieval. Each algorithm was tested individually and then implemented as part of SPIRS. To evaluate the overall system, we first tested the system’s ability to return similar vertebral shapes from the database given a query shape. Initial evaluations using visual queries only (no text) have shown that the system achieves up to 68% accuracy in finding images in the database that exhibit similar abnormality type and severity. Relevance feedback mechanisms have been shown to increase accuracy by an additional 22% after three iterations. While we primarily demonstrate this system in the context of retrieving vertebral shape, our framework has also been adapted to search a collection of 100,000 uterine cervix images to study the progression of

  16. Retrieval of the ultraviolet effective snow albedo during 1998 winter campaign in the French Alps.

    PubMed

    Smolskaia, Irina; Masserot, Dominique; Lenoble, Jacqueline; Brogniez, Colette; de la Casinière, Alain

    2003-03-20

    A measurement campaign was carried out in February 1998 at Briançon Station, French Alps (44.9 degrees N, 6.65 degrees E, 1,310 m above sea level) in order to determine the UV effective snow albedo that was retrieved for both erythemal and UV-A irradiances from measurements and modeling enhancement factors. The results are presented for 15 cloudless days with very variable snow cover and a small snowfall in the middle of the campaign. Erythemal irradiance enhancement due to the surface albedo was found to decrease from approximately +15% to +5% with a jump to +22% after the snowfall, whereas UV-A irradiance enhancement decreased from 7% to 5% and increased to 15% after the snowfall. Thesevalues fit to effective surface albedos of 0.4, 0.1, and 0.5 for erythemal, and to effective albedos of 0.25, 0.1, and 0.4 for UV-A irradiances, respectively. An unexpected difference between the effective albedos retrieved in the two wavelength regions can be explained by the difference of the environment contribution.

  17. Words or concepts: the features of indexing units and their optimal use in information retrieval.

    PubMed Central

    Yang, Y.; Chute, C. G.

    1993-01-01

    Words or Concepts, which are a better choice for indexing the contents of documents? The answer depends on what method is used for retrieval. This paper studies the effects of using canonical concepts versus document words in different retrieval systems with a testing collection of MEDLINE documents. In our tests, for a retrieval system which does not use any human knowledge, using words yielded better retrieval results, while using concepts suffered from a vocabulary difference between canonical expressions of concepts and non-canonical words in queries or documents. For a system which depends on the UMLS synonym set for a mapping from queries or documents to canonical concepts, the retrieval results were slightly better than the case of not using the synonyms, but still worse than the systems using words. For the systems which automatically "learn" empirical connections between words and concepts from examples in the testing collection, the vocabulary problem was effectively solved, and the results of using concepts were competitive or better, compared to those using words. PMID:8130562

  18. A learning-based similarity fusion and filtering approach for biomedical image retrieval using SVM classification and relevance feedback.

    PubMed

    Rahman, Md Mahmudur; Antani, Sameer K; Thoma, George R

    2011-07-01

    This paper presents a classification-driven biomedical image retrieval framework based on image filtering and similarity fusion by employing supervised learning techniques. In this framework, the probabilistic outputs of a multiclass support vector machine (SVM) classifier as category prediction of query and database images are exploited at first to filter out irrelevant images, thereby reducing the search space for similarity matching. Images are classified at a global level according to their modalities based on different low-level, concept, and keypoint-based features. It is difficult to find a unique feature to compare images effectively for all types of queries. Hence, a query-specific adaptive linear combination of similarity matching approach is proposed by relying on the image classification and feedback information from users. Based on the prediction of a query image category, individual precomputed weights of different features are adjusted online. The prediction of the classifier may be inaccurate in some cases and a user might have a different semantic interpretation about retrieved images. Hence, the weights are finally determined by considering both precision and rank order information of each individual feature representation by considering top retrieved relevant images as judged by the users. As a result, the system can adapt itself to individual searches to produce query-specific results. Experiment is performed in a diverse collection of 5 000 biomedical images of different modalities, body parts, and orientations. It demonstrates the efficiency (about half computation time compared to search on entire collection) and effectiveness (about 10%-15% improvement in precision at each recall level) of the retrieval approach.

  19. Rapidly Retargetable Interactive Translingual Retrieval

    DTIC Science & Technology

    2001-01-01

    vocabulary beyond that which was available af- ter term-by-term translation. This is analogous to the process that Singhal et al. applied to monolingual ...Language Evaluation Forum’s (CLEF) multilingual task. We used the English language forms of the queries to retrieve English, French, German, and...tracking task was multilingual , search- ing stories in both English and Mandarin Chinese, and multi-modal, involving both newswire text and broadcast

  20. Improving accuracy for identifying related PubMed queries by an integrated approach.

    PubMed

    Lu, Zhiyong; Wilbur, W John

    2009-10-01

    PubMed is the most widely used tool for searching biomedical literature online. As with many other online search tools, a user often types a series of multiple related queries before retrieving satisfactory results to fulfill a single information need. Meanwhile, it is also a common phenomenon to see a user type queries on unrelated topics in a single session. In order to study PubMed users' search strategies, it is necessary to be able to automatically separate unrelated queries and group together related queries. Here, we report a novel approach combining both lexical and contextual analyses for segmenting PubMed query sessions and identifying related queries and compare its performance with the previous approach based solely on concept mapping. We experimented with our integrated approach on sample data consisting of 1539 pairs of consecutive user queries in 351 user sessions. The prediction results of 1396 pairs agreed with the gold-standard annotations, achieving an overall accuracy of 90.7%. This demonstrates that our approach is significantly better than the previously published method. By applying this approach to a one day query log of PubMed, we found that a significant proportion of information needs involved more than one PubMed query, and that most of the consecutive queries for the same information need are lexically related. Finally, the proposed PubMed distance is shown to be an accurate and meaningful measure for determining the contextual similarity between biological terms. The integrated approach can play a critical role in handling real-world PubMed query log data as is demonstrated in our experiments.