Search results for "statistical [methods]"

Quantum and classical integrability: new approaches in statistical mechanics

1991

Abstract The present status of the statistical mechanics (SM), quantum and classical, of integrable models is reviewed by reporting new results for their partition functions Z obtained for anyon type models in one space and one time (1 + 1) dimensions. The methods of functional integration developed already are extended further. Bose-Fermi equivalence and anyon descriptions are natural parts of the quantum theory and the anyon phase is quantised. The classical integrability is exploited throughout and both classical and quantum integrability theory are reviewed this way, and related to underlying algebraic structures - notably the Hopf algebras (“quantum groups”). A new “ q -boson” lattice …

Adaptive design optimization: a mutual information-based approach to model discrimination in cognitive science.

2010

Discriminating among competing statistical models is a pressing issue for many experimentalists in the field of cognitive science. Resolving this issue begins with designing maximally informative experiments. To this end, the problem to be solved in adaptive design optimization is identifying experimental designs under which one can infer the underlying model in the fewest possible steps. When the models under consideration are nonlinear, as is often the case in cognitive science, this problem can be impossible to solve analytically without simplifying assumptions. However, as we show in this letter, a full solution can be found numerically with the help of a Bayesian computational trick d…

Prevalence of impacted teeth and supernumerary teeth by radiographic evaluation in three Latin American countries: A cross-sectional study

2021

Background Supernumerary teeth are those that exceed the usual dental formula. There are different classifications depending on their anatomical location, shape and number. The objective of this study was to determine the prevalence of impacted and supernumerary teeth in a sample of panoramic radiographs from three Latin American countries. Material and Methods A retrospective and cross-sectional study with a quantitative approach, in which the radiographic observation and analysis of 2000 panoramic radiographs, provided by different radiological centers in Peru, Colombia and Bolivia were performed. An examiner, specialized in Stomatology and Oral Surgery, carried out the radiographic analy…

Impact of fixed orthodontic appliances on quality of life among adolescents in India

2014

Context: Malocclusion can seriously impair quality of life and they may affect various aspects of life, including function, appearance, interpersonal relationships and even career opportunities. Objectives: To assess and determine various factors that may influence the impact of orthodontic treatment on the quality of life of adolescents. Study design: Cross sectional study in adolescents of Moradabad was conducted on 109 males and 113 females (n=222) adolescents having a fixed orthodontic appliance, aged 13 to 22 years (mean 17.5±1.5). A pre-structured questionnaire designed by Mandall et al, with nine conceptual impact sub-scales to highlight the problem faced by the patient in daily life…

Hyoid bone position in different facial skeletal patterns

2018

Background Hyoid bone plays a significant role in physiological functions of craniofacial region and it’s position adapts to changes of the head. The purpose of this study was to determine the position of the hyoid bone among subjects with class I, class II and class III skeletal patterns and evaluate the gender differences. Material and Methods One hundred and ten lateral cephalograms (59 females and 51 males) from different skeletal patterns (class I, II and III) were selected. The skeletal patterns were determined according to ANB angle. Using MicroDicom software, different linear and angular measurements (6 variables) was carried out to determine the position of hyoid bone. Intraclass c…

2021

The aim of the study was to (1) assess the within-session reliability of a unilateral isometric hex bar pull (UIHBP) maximal voluntary contraction (MVC) test and, (2) determine unilateral isometric absolute peak force (PFabs) and relative peak force (PF) values in freeski athletes. Twenty-one male and eight female academy to national team freeskiers performed the novel UIHBP MVC task on a force plate and PFabs and relative PF were assessed (1000 Hz). Within-session measures of PFabs offered high reliability on left and right limbs for males (ICC = 0.91–0.94, CV = 2.6–2.2%) and females (ICC = 0.94–0.94, CV = 1.4–1.6%), while relative PF measures showed good to high reliability in both left a…

Esthetic Assessment of the Effect of Gingival Exposure in the Smile of Patients with Unilateral and Bilateral Maxillary Incisor Agenesis

2014

Purpose: The aim of this study was to determine the dental esthetic perception of the smile of patients with maxillary lateral incisor agenesis (MLIA); the perceptions were examined pre- and post-treatment. Esthetic determinations were made with regard to the gingival exposure in the patients’ smile by orthodontists, general dentists, and laypersons. Materials and Methods: Three hundred eighty one people (80 orthodontists, 181 general dentists, 120 laypersons) rated the attractiveness of the smile in four cases before and after treatment, comprising two cases with unilateral MLIA and contralateral microdontia and two with bilateral MLIA. For each case, the buccal photograph was adjusted usi…

The effect of orthodontic bracket pad shape on shear bond strength, an in vitro study on human enamel

2018

Background To evaluate the effect of bracket pad shape on shear bond strength (SBS) of orthodontic brackets bonded to human enamel. Material and Methods One hundred and five extracted human maxillary permanent molars were divided into 7 groups of 15 specimens per group (n=15). Each group of teeth was bonded with 6 different shaped WildSmiles® brackets (Star, Heart, Soccer ball, Football, Flower, and Diamond) and GAC® rectangle shaped brackets. Shear debonding force was measured with an Instron universal testing machine using a knife-edged chisel 24 hours after initial bonding. Descriptive statistics (mean, standard deviation, and range) for each bracket pad shape was calculated. Analysis of…

Are different generations of CAD/CAM milling machines capable to produce restorations with similar quality?

2016

Background: Different CAD/CAM machinesâ generation may impact the restoration overall quality. The present study evaluated the marginal fit of CAD/CAM restorations manufactured with different generations of CEREC milling unit systems. Material and Methods: Sixteen typodont teeth were divided into two groups (n=8) according to the machineâ s generation assigned. These are control group (G1): Cerec AC with Bluecam/Cerec 3 milling unit and (G2): Cerec AC with Bluecam/MC XL Premium Package milling unit. Scanning of the preparation were performed and crowns were milled using the Vita Mark II blocks. Blocks were cemented using epoxy glue on the pulpal floor only and finger pressure applied for 1 …

The effect of dental chair light exposure duration on shear bond strength of orthodontic brackets : an in vitro study

2018

Background The purpose of this study is to determine if the duration of exposure to the halogen overhead dental chair light has an effect on shear bond strength (SBS) of metal orthodontic brackets. Material and Methods One hundred twenty extracted human lower incisor teeth were divided into six groups (n=20/group). Each group was assigned a predetermined duration of exposure to the halogen dental chair light, set at a fixed distance, before being cured. Light exposure times of 0 minutes (Group 1-Control), 1 minute (Group 2), 2.5 minutes (Group 3), 5 minutes (Group 4), 10 minutes (Group 5), and 15 minutes (Group 6) were tested. Each tooth was subjected to an exclusion criteria examination, s…