8,977 research outputs found
Proximity Full-Text Search with a Response Time Guarantee by Means of Additional Indexes
Full-text search engines are important tools for information retrieval. Term
proximity is an important factor in relevance score measurement. In a proximity
full-text search, we assume that a relevant document contains query terms near
each other, especially if the query terms are frequently occurring words. A
methodology for high-performance full-text query execution is discussed. We
build additional indexes to achieve better efficiency. For a word that occurs
in the text, we include in the indexes some information about nearby words.
What types of additional indexes do we use? How do we use them? These questions
are discussed in this work. We present the results of experiments showing that
the average time of search query execution is 44-45 times less than that
required when using ordinary inverted indexes.
This is a pre-print of a contribution "Veretennikov A.B. Proximity Full-Text
Search with a Response Time Guarantee by Means of Additional Indexes" published
in "Arai K., Kapoor S., Bhatia R. (eds) Intelligent Systems and Applications.
IntelliSys 2018. Advances in Intelligent Systems and Computing, vol 868"
published by Springer, Cham. The final authenticated version is available
online at: https://doi.org/10.1007/978-3-030-01054-6_66. The work was supported
by Act 211 Government of the Russian Federation, contract no 02.A03.21.0006.Comment: Alexander B. Veretennikov. Chair of Calculation Mathematics and
Computer Science, INSM. Ural Federal Universit
Proximity Full-Text Search by Means of Additional Indexes with Multi-component Keys: In Pursuit of Optimal Performance
Full-text search engines are important tools for information retrieval. In a
proximity full-text search, a document is relevant if it contains query terms
near each other, especially if the query terms are frequently occurring words.
For each word in a text, we use additional indexes to store information about
nearby words that are at distances from the given word of less than or equal to
the MaxDistance parameter. We showed that additional indexes with
three-component keys can be used to improve the average query execution time by
up to 94.7 times if the queries consist of high-frequency occurring words. In
this paper, we present a new search algorithm with even more performance gains.
We consider several strategies for selecting multi-component key indexes for a
specific query and compare these strategies with the optimal strategy. We also
present the results of search experiments, which show that three-component key
indexes enable much faster searches in comparison with two-component key
indexes.
This is a pre-print of a contribution "Veretennikov A.B. (2019) Proximity
Full-Text Search by Means of Additional Indexes with Multi-component Keys: In
Pursuit of Optimal Performance." published in "Manolopoulos Y., Stupnikov S.
(eds) Data Analytics and Management in Data Intensive Domains. DAMDID/RCDL
2018. Communications in Computer and Information Science, vol 1003" published
by Springer, Cham. This book constitutes the refereed proceedings of the 20th
International Conference on Data Analytics and Management in Data Intensive
Domains, DAMDID/RCDL 2018, held in Moscow, Russia, in October 2018. The 9
revised full papers presented together with three invited papers were carefully
reviewed and selected from 54 submissions. The final authenticated version is
available online at https://doi.org/10.1007/978-3-030-23584-0_7.Comment: Revised paper of "Veretennikov A.B. Proximity full-text search with a
response time guarantee by means of additional indexes with multi-component
keys", Selected Papers of the XX International Conference on Data Analytics
and Management in Data Intensive Domains (DAMDID/RCDL 2018), Moscow, Russia,
October 9-12, 2018, http://ceur-ws.org/Vol-2277,
http://ceur-ws.org/Vol-2277/paper23.pd
A Comparison of Measured and Self-Reported Blood Pressure Status among Low-Income Housing Residents in New York City
Self-report is widely used to measure hypertension prevalence in population-based studies, but there is little research comparing self-report with measured blood pressure among low-income populations. The objective of this study was to compare self-reported and measured blood pressure status among a sample of low-income housing residents in New York City (n=118). We completed a cross-sectional analysis comparing self-report with measured blood pressure status. We determined the sensitivity, specificity, and positive predictive value (PPV) of each self-report metric. Of the sample, 68.1% was Black, 71.1% had a household income under $25,000/year, and 28.5% did not complete high school. In our study, there was a discrepancy in the prevalence hypertension by self-report (30.5%) versus measurement (39.8%). PPV of self-report was 94.4%. Specificity was 97.2%. Hypertension awareness (sensitivity) was 72.3%. Of individuals not reporting hypertension, 15.9% had measurements in the hypertensive range and 43.9% had measurements in the borderline hypertensive range. Our findings suggest that self-reported and objective measures of hypertension are incongruent among low-income housing residents and may have important implications for population-based research among low-income populations
'Choosing shoes': a preliminary study into the challenges facing clinicians in assessing footwear for rheumatoid patients
Background: Footwear has been accepted as a therapeutic intervention for the foot affected
by rheumatoid arthritis (RA). Evidence relating to the objective assessment of footwear in
patients with RA is limited. The aims of this study were to identify current footwear styles,
footwear characteristics, and factors that influence footwear choice experienced by patients
with RA.
Methods: Eighty patients with RA were recruited from rheumatology clinics during the
summer months. Clinical characteristics, global function, and foot impairment and disability
measures were recorded. Current footwear, footwear characteristics and the factors
associated with choice of footwear were identified. Suitability of footwear was recorded using
pre-determined criteria for assessing footwear type, based on a previous study of foot pain.
Results: The patients had longstanding RA with moderate-to severe disability and
impairment. The foot and ankle assessment demonstrated a low-arch profile with both
forefoot and rearfoot structural deformities. Over 50% of shoes worn by patients were opentype
footwear. More than 70% of patients’ footwear was defined as being poor. Poor
footwear characteristics such as heel rigidity and sole hardness were observed. Patients
reported comfort (17%) and fit (14%) as important factors in choosing their own footwear.
Only five percent (5%) of patients wore therapeutic footwear.
Conclusions: The majority of patients with RA wear footwear that has been previously
described as poor. Future work needs to aim to define and justify the specific features of
footwear that may be of benefit to foot health for people with RA
Status and subdivision of the Parmeener Super-group
Late Palaeozoic and Early Mesozoic rocks of the Parmeener Super-Group
are subdivided on a strict lithostratigraphical basis, and not in the time terms
'Permian' and 'Triassic'
Stump-harvesting for bioenergy probably has transient impacts on abundance, richness and community structure of beetle assemblages
Harvesting of tree stumps for bioenergy is popular and, although the environmental impact has been considered with respect to ecosystem processes, there have been fewer studies on the impact of stump-harvesting on biodiversity. We carried out pitfall-trap surveys of beetle communities at eight plots across four sites (four plots were clear-fells where stumps remained and four were clear-fells where stumps were harvested). Initially, we recovered 7743 beetles when stumps were extracted but still on site (Year 1). All beetles were identified to family level and ground beetles and wood-associated beetles to species level. One year after stumps were extracted, the survey was repeated. In this collection, 2898 individual beetles were recovered. In Year 1, stump-harvesting had a negative impact on beetle abundance and richness. However, 1year after stumps were removed, there were no significant differences in these variables at any site. At the community level, stump-harvesting weakly but significantly, affected carabid composition. Oneyear after stumps were removed, stump-harvesting had no effect on community composition. Stump-harvesting initially negatively affects beetle abundance, family-richness and carabid species richness, as well as community structure, although any effects are not large, are site-specific and are probably not persistent. © 2017 The Royal Entomological Societ
Length- weight relationships, condition factor (K) and relative condition factor (Kn) of Sparids, Dentex congoensis (Maul, 1954) and Dentex angolensis (Maul and Poll, 1953), in Nigerian coastal water
Length-weight relationship and condition factors were estimated for Dentex congoensis and Dentex angolensis of the family sparidae trawled from Nigeria Coastal water in 2009. A total number of 534 specimens ranging from 7.2 – 3.0 cm in total length and 5.4 – 489.8 g in weight were analyzed. The lengthweight relationship is shown by the following equations: LogW –1.610 + 2.791logL (Dentex congoensis) and LogW = -1.558 + 2.776logL (D angolensis). The two species studied exhibited negative allometric growth (b < 3) with the mean b = 2.78 at p < 0.001. The correlation coefficient (R) values were 0.91 (Dentex congoensis) and 0.98 (D angolensis). The condition factor (K) and relative condition factor (Kn) were determined for each species separately. The condition factor (K) obtained for Dentex congoensis and Dentex angolensis were between 0.86 – 8.04 with mean value of 2.48 ± 0.58 and between 2.06 – 6.13 with mean value of 2.79 ± 0.42 respectively. The relative condition factor (Kn) values were 1.28 ±1.09 (Dentex congoensis) and 1.66 ± 2.44 (Dentex anoglensis). The maximum ‘Kn’ values were recorded during the length at first maturity and there was a general decreased in relative condition factor (Kn) with increase length for the two species
Role of the anterior cruciate ligament, anterolateral complex, and lateral meniscus posterior root in anterolateral rotatory knee instability: a biomechanical study
BACKGROUND: Injuries to the anterior cruciate ligament (ACL), Kaplan fibers (KFs), anterolateral capsule/ligament (C/ALL), and lateral meniscus posterior root (LMPR) have been separately linked to anterolateral instability. PURPOSE: To investigate the contributions of the ACL, KFs, C/ALL, and LMPR to knee stability and to measure instabilities resulting from their injury. STUDY DESIGN: Controlled laboratory study. METHODS: Ten fresh-frozen human knees were tested robotically to determine restraints of knee laxity at 0° to 90° of flexion. An 88-N anterior-posterior force (anterior and posterior tibial translation), 5-N·m internal-external rotation, and 8-N·m valgus-varus torque were imposed and intact kinematics recorded. The kinematics were replayed after sequentially cutting the structures (order varied) to calculate their contributions to stability. Another 10 knees were tested in a kinematics rig with optical tracking to measure instabilities after sequentially cutting the structures across 0° to 100° of flexion. One- and 2-way repeated-measures analyses of variance with Bonferroni correction were used to find significance (P 30° of flexion. Combined KFs + C/ALL injury substantially increased anterolateral rotational instability while isolated injury of either did not. LMPR deficiency did not cause significant instability with the ACL intact. CLINICAL RELEVANCE: This study is a comprehensive biomechanical sectioning investigation of the knee stability contributions of the ACL, anterolateral complex, and LMPR and the instability after their transection. The ACL is significant in controlling internal rotation only in extension. In flexion, the KFs are dominant, synergistic with the C/ALL. LMPR tear has an insignificant effect with the ACL intact
Organic Carbon Emissions from the Co-firing of Coal and Wood in a Fixed Bed Combustor
Co-firing of biomass and coal and biomass reduces the emission of pollutants and the overall effects have been extensively studied, but many aspects of the detailed mechanism remain uncertain. A number of studies have been previously made by us of emissions from the combustion in a fixed-bed furnace of bituminous coal and wood, both individually and together, and it was observed that biomass produced less soot and lower NOX emissions. These data are combined with recent measurements of emissions of black carbon (BC) and organic carbon (OC), which are an important source of climate forcing, from the combustion of a number of solid fuels. Conclusion are drawn about the nature of the OC and how the values are dependent on the measurement technique used. Complementary analytical-scale combustion and pyrolysis experiments were also carried out. The results of the analysis of emissions and reaction products, mainly by gas chromatography–mass spectrometry (GC–MS), were interpreted so as to construct a model for pollutant formation during co-firing
An evaluation of seasonal variations in footwear worn by adults with inflammatory arthritis: a cross-sectional observational study using a web-based survey
Background: Foot problems are common in adults with inflammatory arthritis and therapeutic footwear can be
effective in managing arthritic foot problems. Accessing appropriate footwear has been identified as a major barrier,
resulting in poor adherence to treatment plans involving footwear. Indeed, previous New Zealand based studies
found that many people with rheumatoid arthritis and gout wore inappropriate footwear. However, these studies
were conducted in a single teaching hospital during the New Zealand summer therefore the findings may not be
representative of footwear styles worn elsewhere in New Zealand, or reflect the potential influence of seasonal
climate changes. The aim of the study was to evaluate seasonal variations in footwear habits of people with
inflammatory arthritic conditions in New Zealand.
Methods: A cross-sectional study design using a web-based survey. The survey questions were designed to elicit
demographic and clinical information, features of importance when choosing footwear and seasonal footwear
habits, including questions related to the provision of therapeutic footwear/orthoses and footwear experiences.
Results: One-hundred and ninety-seven participants responded who were predominantly women of European
descent, aged between 46–65 years old, from the North Island of New Zealand. The majority of participants
identified with having either rheumatoid arthritis (35%) and/or osteoarthritis (57%) and 68% reported established
disease (>5 years duration). 18% of participants had been issued with therapeutic footwear. Walking and athletic
shoes were the most frequently reported footwear type worn regardless of the time of year. In the summer,
42% reported wearing sandals most often. Comfort, fit and support were reported most frequently as the footwear
features of greatest importance. Many participants reported difficulties with footwear (63%), getting hot feet in the
summer (63%) and the need for a sandal which could accommodate a supportive insole (73%).
Conclusions: Athletic and walking shoes were the most popular style of footwear reported regardless of seasonal
variation. During the summer season people with inflammatory arthritis may wear sandals more frequently in
order to accommodate disease-related foot deformity. Healthcare professionals and researchers should consider
seasonal variation when recommending appropriate footwear, or conducting footwear studies in people with
inflammatory arthritis, to reduce non-adherence to prescribed footwear
- …