scholarly journals The Role of Global Appearance of Omnidirectional Images in Relative Distance and Orientation Retrieval

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3327
Author(s):  
Vicente Román ◽  
Luis Payá ◽  
Adrián Peidró ◽  
Mónica Ballesta ◽  
Oscar Reinoso

Over the last few years, mobile robotics has experienced a great development thanks to the wide variety of problems that can be solved with this technology. An autonomous mobile robot must be able to operate in a priori unknown environments, planning its trajectory and navigating to the required target points. With this aim, it is crucial solving the mapping and localization problems with accuracy and acceptable computational cost. The use of omnidirectional vision systems has emerged as a robust choice thanks to the big quantity of information they can extract from the environment. The images must be processed to obtain relevant information that permits solving robustly the mapping and localization problems. The classical frameworks to address this problem are based on the extraction, description and tracking of local features or landmarks. However, more recently, a new family of methods has emerged as a robust alternative in mobile robotics. It consists of describing each image as a whole, what leads to conceptually simpler algorithms. While methods based on local features have been extensively studied and compared in the literature, those based on global appearance still merit a deep study to uncover their performance. In this work, a comparative evaluation of six global-appearance description techniques in localization tasks is carried out, both in terms of accuracy and computational cost. Some sets of images captured in a real environment are used with this aim, including some typical phenomena such as changes in lighting conditions, visual aliasing, partial occlusions and noise.

Methodology ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Joachim Gerich ◽  
Roland Lehner

Although ego-centered network data provide information that is limited in various ways as compared with full network data, an ego-centered design can be used without the need for a priori and researcher-defined network borders. Moreover, ego-centered network data can be obtained with traditional survey methods. However, due to the dynamic structure of the questionnaires involved, a great effort is required on the part of either respondents (with self-administration) or interviewers (with face-to-face interviews). As an alternative, we will show the advantages of using CASI (computer-assisted self-administered interview) methods for the collection of ego-centered network data as applied in a study on the role of social networks in substance use among college students.


2019 ◽  
Author(s):  
Alexia Bourgeois ◽  
Carole Guedj ◽  
Emmanuel Carrera ◽  
Patrik Vuilleumier

Selective attention is a fundamental cognitive function that guides behavior by selecting and prioritizing salient or relevant sensory information of our environment. Despite early evidence and theoretical proposal pointing to an implication of thalamic control in attention, most studies in the past two decades focused on cortical substrates, largely ignoring the contribution of subcortical regions as well as cortico-subcortical interactions. Here, we suggest a key role of the pulvinar in the selection of salient and relevant information via its involvement in priority maps computation. Prioritization may be achieved through a pulvinar- mediated generation of alpha oscillations, which may then modulate neuronal gain in thalamo-cortical circuits. Such mechanism might orchestrate the synchrony of cortico-cortical interaction, by rendering neural communication more effective, precise and selective. We propose that this theoretical framework will support a timely shift from the prevailing cortico- centric view of cognition to a more integrative perspective of thalamic contributions to attention and executive control processes.


2019 ◽  
Vol 15 (3) ◽  
pp. 156-158
Author(s):  
Aditi Priyamvara ◽  
Amit K. Dey ◽  
Antara Bagchi ◽  
Raveena Kelkar ◽  
Rajaram Sharma

Background: It is known that hormonal imbalances during pregnancy make women more susceptible to dental problems. High levels of progesterone and estrogen during pregnancy, lead to an increased inflammatory response to dental plaque thus causing predisposing to gum diseases such as gingivitis. If untreated, gingivitis leads to chronic periodontitis which may manifest systemically in form of cardiovascular, endocrine or even respiratory disorders. Also, hyperacidity in the oral cavity due to gastric reflux and vomiting leads to decreased pH thus damaging the tooth enamel making the oral cavity more prone to tooth decay and tooth loss. Studies also show that periodontal disease can also lead to adverse pregnancy outcomes such as pre-term and low birth weight babies. Objectives: We sought to understand the role of oral health in pregnancy. Methods: We identified major articles of interest in the field of oral health in pregnancy and drafted a mini-symposium based on relevant information. Conclusion: Regular dental visits and cognizant efforts to sustain a healthy oral environment can help women in the prevention and treatment of dental issues during pregnancy. The paper highlights the common oral manifestations during pregnancy and their local and systemic impact on the body during pregnancy. Furthermore, it also emphasizes the importance of good oral health practices to counteract the oral complications and the significance of oral health awareness in pregnant women.


2020 ◽  
Vol 22 (1) ◽  
pp. 92-97
Author(s):  
KONSTANTIN A. KORSIK ◽  
◽  
ANASTASIYA A. PARFENCHIKOVA ◽  

The article is devoted to the review of current changes in the legislation on notaries related to the development of electronic civil circulation, analysis of existing digital risks and assessment of the role of notaries in combating them. In modern economic realities, a significant expansion of the sphere of competence of the notary is carried out by introducing completely new notarial actions into the scope of the notary’s terms of reference. At the same time, the notary does not just follow the general ‘digital’ trend, but independently makes significant efforts to effectively perform the tasks of the social sphere regulator assigned to it by the state. The creation of the Unified Notary Information System as part of the formation of the technological infrastructure to ensure the security and stability of legal relations in the context of electronic civil circulation takes to a new level the quality of notarial services and the security of legally relevant information. The role of notaries significantly increases in conditions when the use of digital technologies in the economy, public administration, social sphere becomes one of the main vectors of world development, and society and the state inevitably face the flip side of this process – digital risks that jeopardize the safety of participants in civil turnover and their property. In 2020, as part of the implementation of the national program ‘Digital Economy’, it is planned to introduce a number of innovations that will create the basis for a stable and secure ‘digital’ turnover.


2021 ◽  
pp. 216770262095934
Author(s):  
Julia M. Sheffield ◽  
Holger Mohr ◽  
Hannes Ruge ◽  
Deanna M. Barch

Rapid instructed task learning (RITL) is the uniquely human ability to transform task information into goal-directed behavior without relying on trial-and-error learning. RITL is a core cognitive process supported by functional brain networks. In patients with schizophrenia, RITL ability is impaired, but the role of functional network connectivity in these RITL deficits is unknown. We investigated task-based connectivity of eight a priori network pairs in participants with schizophrenia ( n = 29) and control participants ( n = 31) during the performance of an RITL task. Multivariate pattern analysis was used to determine which network connectivity patterns predicted diagnostic group. Of all network pairs, only the connectivity between the cingulo-opercular network (CON) and salience network (SAN) during learning classified patients and control participants with significant accuracy (80%). CON-SAN connectivity during learning was significantly associated with task performance in participants with schizophrenia. These findings suggest that impaired interactions between identification of salient stimuli and maintenance of task goals contributes to RITL deficits in participants with schizophrenia.


Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 552
Author(s):  
Salam Awenat ◽  
Arnoldo Piccardo ◽  
Patricia Carvoeiras ◽  
Giovanni Signore ◽  
Luca Giovanella ◽  
...  

Background: The use of prostate-specific membrane antigen (PSMA)-targeted agents for staging prostate cancer (PCa) patients using positron emission tomography/computed tomography (PET/CT) is increasing worldwide. We performed a systematic review on the role of 18F-PSMA-1007 PET/CT in PCa staging to provide evidence-based data in this setting. Methods: A comprehensive computer literature search of PubMed/MEDLINE and Cochrane Library databases for studies using 18F-PSMA-1007 PET/CT in PCa staging was performed until 31 December 2020. Eligible articles were selected and relevant information was extracted from the original articles by two authors independently. Results: Eight articles (369 patients) evaluating the role of 18F-PSMA-1007 PET/CT in PCa staging were selected. These studies were quite heterogeneous, but, overall, they demonstrated a good diagnostic accuracy of 18F-PSMA-1007 PET/CT in detecting PCa lesions at staging. Overall, higher primary PCa aggressiveness was associated with higher 18F-PSMA-1007 uptake. When compared with other radiological and scintigraphic imaging methods, 18F-PSMA-1007 PET/CT had superior sensitivity in detecting metastatic disease and the highest inter-reader agreement. 18F-PSMA-1007 PET/CT showed similar results in terms of diagnostic accuracy for PCa staging compared with PET/CT with other PSMA-targeted tracers. Dual imaging with multi-parametric magnetic resonance imaging and 18F-PSMA-1007 PET/CT may improve staging of primary PCa. Notably, 18F-PSMA-1007-PET/CT may detect metastatic disease in a significant number of patients with negative standard imaging. Conclusions: 18F-PSMA-1007 PET/CT demonstrated a good accuracy in PCa staging, with similar results compared with other PSMA-targeted radiopharmaceuticals. This method could substitute bone scintigraphy and conventional abdominal imaging for PCa staging. Prospective multicentric studies are needed to confirm these findings.


2016 ◽  
Vol 23 (3) ◽  
pp. 600 ◽  
Author(s):  
Uba Backonja ◽  
Nai-Ching Chi ◽  
Yong Choi ◽  
Amanda K Hall ◽  
Thai Le ◽  
...  

Background: Health technologies have the potential to support the growing number of older adults who are aging in place. Many tools include visualizations (data visualizations, visualizations of physical representations). However, the role of visualizations in supporting aging in place remains largely unexplored.Objective: To synthesize and identify gaps in the literature evaluating visualizations (data visualizations and visualizations of physical representations), for informatics tools to support healthy aging.Methods: We conducted a search in CINAHL, Embase, Engineering Village, PsycINFO, PubMed, and Web of Science using a priori defined terms for publications in English describing community-based studies evaluating visualizations used by adults aged ≥65 years.Results: Six out of the identified 251 publications were eligible. Most studies were user studies and varied methodological quality. Three visualizations of virtual representations supported performing at-home exercises. Participants found visual representations either (a) helpful, motivational, and supported their understanding of their health behaviors or (b) not an improvement over alternatives. Three data visualizations supported understanding of one’s health. Participants were able to interpret data visualizations that used precise data and encodings that were more concrete better than those that did not provide precision or were abstract. Participants found data visualizations helpful in understanding their overall health and granular data.Conclusions: Studies we identified used visualizations to promote engagement in exercises or understandings of one’s health. Future research could overcome methodological limitations of studies we identified to develop visualizations that older adults could use with ease and accuracy to support their health behaviors and decision-making.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jade B. Jackson ◽  
Eva Feredoes ◽  
Anina N. Rich ◽  
Michael Lindner ◽  
Alexandra Woolgar

AbstractDorsolateral prefrontal cortex (dlPFC) is proposed to drive brain-wide focus by biasing processing in favour of task-relevant information. A longstanding debate concerns whether this is achieved through enhancing processing of relevant information and/or by inhibiting irrelevant information. To address this, we applied transcranial magnetic stimulation (TMS) during fMRI, and tested for causal changes in information coding. Participants attended to one feature, whilst ignoring another feature, of a visual object. If dlPFC is necessary for facilitation, disruptive TMS should decrease coding of attended features. Conversely, if dlPFC is crucial for inhibition, TMS should increase coding of ignored features. Here, we show that TMS decreases coding of relevant information across frontoparietal cortex, and the impact is significantly stronger than any effect on irrelevant information, which is not statistically detectable. This provides causal evidence for a specific role of dlPFC in enhancing task-relevant representations and demonstrates the cognitive-neural insights possible with concurrent TMS-fMRI-MVPA.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Sansit Patnaik ◽  
Fabio Semperlotti

AbstractThis study presents the formulation, the numerical solution, and the validation of a theoretical framework based on the concept of variable-order mechanics and capable of modeling dynamic fracture in brittle and quasi-brittle solids. More specifically, the reformulation of the elastodynamic problem via variable and fractional-order operators enables a unique and extremely powerful approach to model nucleation and propagation of cracks in solids under dynamic loading. The resulting dynamic fracture formulation is fully evolutionary, hence enabling the analysis of complex crack patterns without requiring any a priori assumption on the damage location and the growth path, and without using any algorithm to numerically track the evolving crack surface. The evolutionary nature of the variable-order formalism also prevents the need for additional partial differential equations to predict the evolution of the damage field, hence suggesting a conspicuous reduction in complexity and computational cost. Remarkably, the variable-order formulation is naturally capable of capturing extremely detailed features characteristic of dynamic crack propagation such as crack surface roughening as well as single and multiple branching. The accuracy and robustness of the proposed variable-order formulation are validated by comparing the results of direct numerical simulations with experimental data of typical benchmark problems available in the literature.


2019 ◽  
Vol 116 (19) ◽  
pp. 9463-9468 ◽  
Author(s):  
Katherine S. Geist ◽  
Joan E. Strassmann ◽  
David C. Queller

Evolutionary conflict can drive rapid adaptive evolution, sometimes called an arms race, because each party needs to respond continually to the adaptations of the other. Evidence for such arms races can sometimes be seen in morphology, in behavior, or in the genes underlying sexual interactions of host−pathogen interactions, but is rarely predicted a priori. Kin selection theory predicts that conflicts of interest should usually be reduced but not eliminated among genetic relatives, but there is little evidence as to whether conflict within families can drive rapid adaptation. Here we test multiple predictions about how conflict over the amount of resources an offspring receives from its parent would drive rapid molecular evolution in seed tissues of the flowering plant Arabidopsis. As predicted, there is more adaptive evolution in genes expressed in Arabidopsis seeds than in other specialized organs, more in endosperms and maternal tissues than in embryos, and more in the specific subtissues involved in nutrient transfer. In the absence of credible alternative hypotheses, these results suggest that kin selection and conflict are important in plants, that the conflict includes not just the mother and offspring but also the triploid endosperm, and that, despite the conflict-reducing role of kinship, family members can engage in slow but steady tortoise-like arms races.


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