Top- \(k\) Approximate Answers to XPath Queries with Negation

2014 ◽  
Vol 26 (10) ◽  
pp. 2561-2573 ◽  
Author(s):  
Bettina Fazzinga ◽  
Sergio Flesca ◽  
Andrea Pugliese
Keyword(s):  
Approximate Answers

Approximate Processing for Medical Record Linking and Multidatabase Analysis

2011 ◽  
pp. 2203-2217
Author(s):  
Qing Zhang
Keyword(s):  
Query Processing ◽  
Medical Record ◽  
Approximate Query Processing ◽  
Related Data ◽  
Multidatabase Systems ◽  
Aggregate Queries ◽  
Health Related ◽  
Approximate Query ◽  
Approximate Answers ◽  
Query Planning

In this article we investigate how approximate query processing (AQP) can be used in medical multidatabase systems. We identify two areas where this estimation technique will be of use. First, approximate query processing can be used to preprocess medical record linking in the multidatabase. Second, approximate answers can be given for aggregate queries. In the case of multidatabase systems used to link health and health related data sources, preprocessing can be used to find records related to the same patient. This may be the first step in the linking strategy. If the aim is to gather aggregate statistics, then the approximate answers may be enough to provide the required answers. At least they may provide initial answers to encourage further investigation. This estimation may also be used for general query planning and optimization, important in multidatabase systems. In this article we propose two techniques for the estimation. These techniques enable synopses of component local databases to be precalculated and then used for obtaining approximate results for linking records and for aggregate queries. The synopses are constructed with restrictions on the storage space. We report on experiments which show that good approximate results can be obtained in a much shorter time than performing the exact query.

Ganser syndrome: Review and case report

2016 ◽  
Vol 33 (S1) ◽  
pp. S363-S363
Author(s):  
R. Faria ◽  
D. Brandão ◽  
T. Novo ◽  
L. Quintela ◽  
A. Fonte
Keyword(s):  
Rare Condition ◽  
Acute Onset ◽  
Factitious Disorder ◽  
Gradual Improvement ◽  
Antipsychotic Medications ◽  
Blood Tests ◽  
Approximate Answers ◽  
Competing Interest ◽  
Motor Abnormalities

IntroductionFirst described by Sigbert Ganser in 1987, Ganser syndrome consists in a rare condition, characterized by the following four clinical features: approximate answers, dulling of consciousness, conversion symptoms and hallucinations.ObjectivesTo present a case suggestive of Ganser Syndrome and to review the literature with particular regard to the aetiology of this condition.MethodsLiterature review, using computerized databases (MEDLINE®, Medscape®). Articles were selected based on the content of their abstract and their relevance.ResultsA 58-year-old woman was admitted to a Psychiatric Unit of a General Hospital for presenting behavioural abnormalities of acute onset. During hospitalization, the patient displayed indifference, incoherent speech with approximate answers, motor abnormalities and auditory psedudohallucinations. The patient was evaluated by a neurologist and various exams were performed (blood tests, CT, MRI, EEG) that showed no significant abnormalities. Pharmacological treatment consisted of antidepressant and antipsychotic medications. During the follow-up, there was a slow but gradual improvement of symptoms. Six months after hospitalization the patient decide to end up the follow-up.ConclusionsLittle is still known about Ganser Syndrome. The four aetiological perspectives consider: hysterical origin, malingering or factitious disorder, psychotic origin and organic origin. The lack of reports and information about Ganser syndrome made it worthwhile reporting this case.Disclosure of interestThe authors have not supplied their declaration of competing interest.

A Second Visually Impaired, Mentally Retarded Male with Pervasive Developmental Disorder, Tourette Disorder and Ganser's Syndrome: Diagnostic Classification and Treatment

1987 ◽  
Vol 16 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Jacob Kerbeshian ◽  
Larry Burd
Keyword(s):  
Pervasive Developmental Disorder ◽  
Visually Impaired ◽  
Developmental Disorder ◽  
Mentally Retarded ◽  
Intervention Strategies ◽  
Diagnostic Classification ◽  
Approximate Answers ◽  
Tourette Disorder ◽  
Retarded Male ◽  
Classification And Treatment

The authors report a second visually impaired, mentally retarded male who presents with symptoms consistent with atypical pervasive developmental disorder, Tourette disorder, and a syndrome of approximate answers (Ganser's syndrome). Both this case and an earlier reported case are significant in that they identify two children with strikingly similar long-standing symptoms and developmental histories. Since these findings may have broader relevance to children with multiple coexisting disorders, diagnostic and intervention strategies in this population are reviewed.

Data Streams

2011 ◽  
pp. 561-565
Author(s):  
João Gama ◽  
Pedro Pereira Rodrigues
Keyword(s):  
Decision Support ◽  
Data Analysis ◽  
Data Base ◽  
Data Streams ◽  
Active Role ◽  
Analysis Data ◽  
Current Data ◽  
Data Mining Algorithms ◽  
Exact Answer ◽  
Approximate Answers

Nowadays, data bases are required to store massive amounts of data that are continuously inserted, and queried. Organizations use decision support systems to identify potential useful patterns in data. Data analysis is complex, interactive, and exploratory over very large volumes of historic data, eventually stored in distributed environments. What distinguishes current data sources from earlier ones are the continuous flow of data and the automatic data feeds. We do not just have people who are entering information into a computer. Instead, we have computers entering data into each other (Muthukrishnan, 2005). Some illustrative examples of the magnitude of today data include: 3 billion telephone calls per day, 4 Giga Bytes of data from radio telescopes every night, 30 billion emails per day, 1 billion SMS, 5 Giga Bytes of Satellite Data per day, 70 billion IP Network Traffic per day. In these applications, data is modelled best not as persistent tables but rather as transient data streams. In some applications it is not feasible to load the arriving data into a traditional Data Base Management Systems (DBMS), and traditional DBMS are not designed to directly support the continuous queries required in these applications (Alon et al., 1996; Babcock et al. 2002; Cormode & Muthukrishnan, 2003). These sources of data are called Data Streams. Computers play a much more active role in the current trends in decision support and data analysis. Data mining algorithms search for hypothesis, evaluate and suggest patterns. The pattern discovery process requires online ad-hoc queries, not previously defined, that are successively refined. Due to the exploratory nature of these queries, an exact answer may be not required: a user may prefer a fast but approximate answer to a exact but slow answer. Processing queries in streams require radically different type of algorithms. Range queries and selectivity estimation (the proportion of tuples that satisfy a query) are two illustrative examples where fast but approximate answers are more useful than slow and exact ones. Approximate answers are obtained from small data structures (synopsis) attached to data base that summarize information and can be updated incrementally

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