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Salient Points (salient + point)

Distribution by Scientific Domains

Medical Sciences	42%

Selected Abstracts

Sparse points matching by combining 3D mesh saliency with statistical descriptors

COMPUTER GRAPHICS FORUM, Issue 2 2008
U. Castellani
Abstract This paper proposes new methodology for the detection and matching of salient points over several views of an object. The process is composed by three main phases. In the first step, detection is carried out by adopting a new perceptually-inspired 3D saliency measure. Such measure allows the detection of few sparse salient points that characterize distinctive portions of the surface. In the second step, a statistical learning approach is considered to describe salient points across different views. Each salient point is modelled by a Hidden Markov Model (HMM), which is trained in an unsupervised way by using contextual 3D neighborhood information, thus providing a robust and invariant point signature. Finally, in the third step, matching among points of different views is performed by evaluating a pairwise similarity measure among HMMs. An extensive and comparative experimental session has been carried out, considering real objects acquired by a 3D scanner from different points of view, where objects come from standard 3D databases. Results are promising, as the detection of salient points is reliable, and the matching is robust and accurate. [source]

A new look at the derivation of the Schrödinger equation from Newtonian mechanics

ANNALEN DER PHYSIK, Issue 6 2003
L. Fritsche
Abstract We present a modified version of Nelson's seminal paper on the derivation of the time-dependent Schrödinger equation which draws on the equation of motion of a particle that moves under the influence of a classical force field and additional stochastic forces. The emphasis of our elaboration is focused on the implication of allowing stochastic forces to occur, viz. that the energy E of the particle is no longer conserved on its trajectory in a conservative force field. We correlate this departure , E from its classical energy with the energy/time uncertainty relation where , t is the average time for , E to persist. The stability of atoms, the zero-point energy of oscillators, the tunneling effect and the diffraction at slits are shown to be directly connected with the occurrence of such energy fluctuations. We discuss and rederive Nelson's theory entirely from this point of view and generalize his approach to systems of N particles which interact via pair forces. Achieving reversibility in a description of particle motion that is akin to Brownian motion, represents a salient point of the derivation. We demonstrate that certain objections raised against Nelson's theory are without substance. We also try to put the particular worldview of this version of stochastic quantum mechanics into perspective with regard to the established Copenhagen interpretation. [source]

Sparse points matching by combining 3D mesh saliency with statistical descriptors

Cross-sectional studies in prescribing research

JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 6 2001
J. Jesson BSc PhD
A cross-sectional study aims to describe the overall picture of a phenomenon, a situational problem, an attitude or an issue, by asking a cross-section of a given population at one specified moment in time. This paper describes the key features of the cross-sectional survey method. It begins by highlighting the main principles of the method, then discusses stages in the research process, drawing on two surveys of primary care pharmacists to illustrate some salient points about planning, sampling frames, definition and conceptual issues, research instrument design and response rates. Four constraints in prescribing studies were noted. First the newness of the subject meant a low basis of existing knowledge to design a questionnaire. Second, there was no public existing database for the sampling frame, so a pragmatic sampling exercise was used. Third, the definition of a Primary Care Pharmacist (PCP) [in full] and respondents recognition of that name and identification with the new role limited the response. Fourth, a growing problem for all surveys, but particularly with pharmacists and general practitioners (GP) [in full] is the growing danger of survey fatigue, which has a negative impact on response levels. [source]

12 Highly Interactive Teaching: A "HIT" with Residents

ACADEMIC EMERGENCY MEDICINE, Issue 2008
Linda Regan
Covering the core content of emergency medicine during residency training is both a time consuming and challenging endeavor. One of the more significant challenges in graduate medical education is to develop more interactive, less didactic teaching modalities. In an attempt to develop a more interactive educational curriculum, we interspersed weekly sessions titled "Highly Interactive Teaching" (HIT) with standard formal lecture didactics. A primary focus of many educators in emergency medicine is teaching residents how to manage the undifferentiated patient. To this end, we revised our curriculum to include 34 four-hour symptom/chief complaint-based sessions. The first hour is an introductory lecture on the general approach to a patient with the specified complaint. Residents then divide into small groups which rotate through specific case-based sections covering varied diagnoses which might present with the symptom complaint. These faculty-run small groups use a case-based approach, either high or low simulation-based or oral boards-based format. Each faculty then is required to sum up the salient points of their section. The final hour of the day is an evidenced-based review of supporting literature. Residents are required to read and critique selected articles for the audience so that the basis for diagnosis and management decisions can be discussed as a large group discussion. We believe this change in format will help residents not only to become more active learners, but also to become more astute clinicians. [source]

Right ventricular involvement in hypertrophic cardiomyopathy: A case report and literature review

CLINICAL CARDIOLOGY, Issue 1 2001
Dariush Mozaffarian M.D.
Abstract Although hypertrophic cardiomyopathy (HCM) is classically considered a disease of the left ventricle, right ventricular (RV) abnormalities have also been reported. However, involvement of the right ventricle in HCM has not been extensively characterized. The literature regarding prevalence, genetics, patterns of involvement, histologic findings, symptoms, diagnosis, and treatment of RV abnormalities in HCM is reviewed. To highlight the salient points, a case is presented of apical HCM with significant RV involvement, with an RV outflow tract gradient and near obliteration of the RV cavity, in the absence of a left intraventricular gradient. Right ventricular involvement in HCM appears to be as heterogeneous as that of the left ventricle. The spectrum extends from mild concentric hypertrophy to more unusual severe, obstructive disease. While in some cases the extent of RV involvement correlates with left ventricular (LV) involvement, predominant RV disease can be seen as well. While the genetics of RV involvement have not been well characterized, histologic findings appear to be similar to those in the left ventricle, suggesting similar pathogenesis. Significant RV involvement may result in RV outflow obstruction and/or reduced RV diastolic filling, with potentially increased incidence of severe dyspnea, supraventricular arrhythmias, and pulmonary thromboembolism. The optimal treatment for patients with significant RV disease is unknown. Medical and surgical therapies have been attempted with variable success; experience with newer techniques such as percutaneous catheter ablation has not been reported. Further characterization of RV involvement in HCM is necessary to elucidate more clearly the clinical features and optimal treatments of this manifestation of HCM. [source]