18,856 research outputs found

    The relationship between IR and multimedia databases

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    Modern extensible database systems support multimedia data through ADTs. However, because of the problems with multimedia query formulation, this support is not sufficient.\ud \ud Multimedia querying requires an iterative search process involving many different representations of the objects in the database. The support that is needed is very similar to the processes in information retrieval.\ud \ud Based on this observation, we develop the miRRor architecture for multimedia query processing. We design a layered framework based on information retrieval techniques, to provide a usable query interface to the multimedia database.\ud \ud First, we introduce a concept layer to enable reasoning over low-level concepts in the database.\ud \ud Second, we add an evidential reasoning layer as an intermediate between the user and the concept layer.\ud \ud Third, we add the functionality to process the users' relevance feedback.\ud \ud We then adapt the inference network model from text retrieval to an evidential reasoning model for multimedia query processing.\ud \ud We conclude with an outline for implementation of miRRor on top of the Monet extensible database system

    Techniques for improving efficiency and scalability for the integration of information retrieval and databases

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    PhDThis thesis is on the topic of integration of Information Retrieval (IR) and Databases (DB), with particular focuses on improving efficiency and scalability of integrated IR and DB technology (IR+DB). The main purpose of this study is to develop efficient and scalable techniques for supporting integrated IR and DB technology, which is a popular approach today for handling complex queries over text and structured data. Our specific interest in this thesis is how to efficiently handle queries over large-scale text and structured data. The work is based on a technology that integrates probability theory and relational algebra, where retrievals for text and data are to be expressed in probabilistic logical programs such as probabilistic relational algebra or probabilistic Datalog. To support efficient processing of probabilistic logical programs, we proposed three optimization techniques that focus on aspects covered logical and physical layers, which include: scoring-driven query optimization using scoring expression, query processing with top-k incorporated pipeline, and indexing with relational inverted index. Specifically, scoring expressions are proposed for expressing the scoring or probabilistic semantics of implied scoring functions of PRA expressions, so that efficient query execution plan can be generated by rule-based scoring-driven optimizer. Secondly, to balance efficiency and effectiveness so that to improve query response time, we studied methods for incorporating topk algorithms into pipelined query execution engine for IR+DB systems. Thirdly, the proposed relational inverted index integrates IR-style inverted index and DB-style tuple-based index, which can be used to support efficient probability estimation and aggregation as well as conventional relational operations. Experiments were carried out to investigate the performances of proposed techniques. Experimental results showed that the efficiency and scalability of an IR+DB prototype have been improved, while the system can handle queries efficiently on considerable large data sets for a number of IR tasks

    Polysemy and brevity versus frequency in language

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    The pioneering research of G. K. Zipf on the relationship between word frequency and other word features led to the formulation of various linguistic laws. The most popular is Zipf's law for word frequencies. Here we focus on two laws that have been studied less intensively: the meaning-frequency law, i.e. the tendency of more frequent words to be more polysemous, and the law of abbreviation, i.e. the tendency of more frequent words to be shorter. In a previous work, we tested the robustness of these Zipfian laws for English, roughly measuring word length in number of characters and distinguishing adult from child speech. In the present article, we extend our study to other languages (Dutch and Spanish) and introduce two additional measures of length: syllabic length and phonemic length. Our correlation analysis indicates that both the meaning-frequency law and the law of abbreviation hold overall in all the analyzed languages

    Information Discovery on Electronic Health Records Using Authority Flow Techniques

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    <p>Abstract</p> <p>Background</p> <p>As the use of electronic health records (EHRs) becomes more widespread, so does the need to search and provide effective information discovery within them. Querying by keyword has emerged as one of the most effective paradigms for searching. Most work in this area is based on traditional Information Retrieval (IR) techniques, where each document is compared individually against the query. We compare the effectiveness of two fundamentally different techniques for keyword search of EHRs.</p> <p>Methods</p> <p>We built two ranking systems. The traditional BM25 system exploits the EHRs' content without regard to association among entities within. The Clinical ObjectRank (CO) system exploits the entities' associations in EHRs using an authority-flow algorithm to discover the most relevant entities. BM25 and CO were deployed on an EHR dataset of the cardiovascular division of Miami Children's Hospital. Using sequences of keywords as queries, sensitivity and specificity were measured by two physicians for a set of 11 queries related to congenital cardiac disease.</p> <p>Results</p> <p>Our pilot evaluation showed that CO outperforms BM25 in terms of sensitivity (65% vs. 38%) by 71% on average, while maintaining the specificity (64% vs. 61%). The evaluation was done by two physicians.</p> <p>Conclusions</p> <p>Authority-flow techniques can greatly improve the detection of relevant information in EHRs and hence deserve further study.</p

    Naval Surface Warfare Center Dahlgren Division Engagement Systems (G) Department Development of a Plan to Maintain, Expand, and Create Corporate Knowledge

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    This dissertation presents the implementation of an organizational study in a technical organization that provides basic information for proper decision making to establish, continue, nurture, modify, transfer or terminate a Knowledge Management (KM) practice. Different aspects of an organization influence the capability to create and retain knowledge. Understanding the factors and the environment of the KM problem in an organization is essential for a successful plan and execution of knowledge creation, transfer and retention. The study purpose was to describe the contextual situation of the organization in terms of Human, Structural and Relational Capital; identify critical knowledge for the organization and knowledge at risk; and identify barriers for knowledge transfer and knowledge retention. The method presented in this project can partially fulfill the development of solutions per the objectives of this project. The actions recommended as a result of this study will help modify the organizational culture to support an environment of knowledge sharing. The study results also provide a baseline for KM metrics in areas that were not previously tracked by the organization. Limitations to the methodology were identified. Not enough participants answered the survey to identify knowledge at risk. The execution of this project and the study results support that KM can provide a structured approach for the development of solutions to the selected goals. Furthermore, it helps changing strategic objectives into specific actions supported by empirical data that can be executed at the working level of the organization. The study identifies what KM efforts are needed to continue to be used, modified, disregarded or implemented to meet the organization\u27s KM objectives

    Effect of Intellectual Capital on Competitive Advantage in the Jordanian Pharmaceutical Companies

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    The current study is considered as a quantitative explanatory study aims to examine the effect of intellectual capital (human, relational and structural capital) on competitive advantage in Jordanian pharmaceutical companies. In addition, it aims to explore awareness of the importance of intellectual capital and dimensions of competitive advantage in the targeted companies A survey strategy was applied thorough a self-administrated questionnaire as the data collection method. 13 pharmaceutical companies that were registered in the Jordanian Association of Pharmaceutical manufacturers (JAMP) in 2016 were targeted in this study. The total number of all general managers, deputy managers, head of departments and head of divisions in the 13 companies was 220 they were all targeted, however, 207 questionnaires were returned. Statistical tests within SPSS package were used to analyze the data. Results show strong statistical significant effect of intellectual capital (human capital, relational capital and structural capital) on competitive advantage in the Jordanian pharmaceutical companies at level (α ≤ 0.05). Findings also indicate that each of the intellectual capital constructs has its own effect on the competitive advantage.  According the results indicated for the awareness of the management in these companies to the importance of managing intellectual capital. For the awareness of competitive advantage dimensions the results revealed a moderate level of importance as addressed by the respondent of the study. The study has made significant contributions to the body of knowledge at academic and practical levels by extending knowledge regarding the effect of intellectual capital on competitive advantage . this study answers the call by many researchers for more studies to address the relationship the study constructs in emerging economies. Practically the study recommends that Jordanian pharmaceutical companies must provide training programs to support staff with specialized skill related to their jobs and tasks.  It is also recommended that recruiting and selection employees' process should consider professional and social applicants' competencies. Keywords: intellectual capital; competitive advantage; human capital; relational capital; structural capital; pharmaceutical; Jordan
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