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2021 ◽  
Vol 10 (10) ◽  
pp. 671
Author(s):  
Marcello La La Guardia ◽  
Filippo D’Ippolito ◽  
Maurizio Cellura

The recent diffusion of RES (Renewable Energy Sources), considering the electric energy produced by photovoltaic and wind plants, brought to light the problem of the unpredictable nature of wind and solar energy. P2G (Power to Gas) implementation seems to be the right solution, transforming curtailed energy in hydrogen. The choice of the settlement of P2G plants is linked to many factors like the distances between the gas grid and the settlement of RES plants, the transportation networks, the energy production, and population distribution. In light of this, the implementation of a Multi-Criteria Analysis (MCA) into a Geographic Information System (GIS) processing represents a good strategy to achieve the goal in a specific territorial asset. In this work, this method has been applied to the case of study of Sicily (Italy). The paper shows in detail the geomatic semi-automated processing that allows to find the set of possible solutions and further to choose the best localization for new P2G plants, connected to a Relational Database Management System (RDBMS) and integrated with a WebGIS visualization for real-time analysis. This system is useful for the management, the development, and the study of hydrogen technologies, in order to link the electrical network and the gas network datasets with economical and infrastructural assets through GIS processing. In the future new factors will join in the process as policies on hydrogen take shape.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Wenxiu He ◽  
Fangfang Lu ◽  
Jingjing Chen ◽  
Yi Ruan ◽  
Tingjuan Lu ◽  
...  

Wireless sensors localization is still the main problem concerning wireless sensor networks (WSN). Unfortunately, range-free node localization of WSN results in a fatal weakness–, low accuracy. In this paper, we introduce kernel regression to node localization of anisotropic WSN, which transfers the problem of localization to the problem of kernel regression. Radial basis kernel-based G-LSVR and polynomial-kernel-based P-LSVR proposed are compared with classical DV-Hop in both isotropic WSN and anisotropic WSN under different proportion beacons, network scales, and disturbances of communication range. G-LSVR presents the best localization accuracy and stability from the simulation results.


2021 ◽  
Vol 11 (2) ◽  
pp. 99
Author(s):  
Gianluca Franceschini ◽  
Elena Jane Mason ◽  
Cristina Grippo ◽  
Sabatino D’Archi ◽  
Anna D’Angelo ◽  
...  

Breast conserving surgery has become the standard of care and is more commonly performed than mastectomy for early stage breast cancer, with recent studies showing equivalent survival and lower morbidity. Accurate preoperative lesion localization is mandatory to obtain adequate oncological and cosmetic results. Image guidance assures the precision requested for this purpose. This review provides a summary of all techniques currently available, ranging from the classic wire positioning to the newer magnetic seed localization. We describe the procedures and equipment necessary for each method, outlining the advantages and disadvantages, with a focus on the cost-effective preoperative skin tattoo technique performed at our centre. Breast surgeons and radiologists have to consider ongoing technological developments in order to assess the best localization method for each individual patient and clinical setting.


2020 ◽  
Vol 220 (3) ◽  
pp. 532 ◽  
Author(s):  
Sophie Dream ◽  
Tracy S. Wang
Keyword(s):  

2020 ◽  
pp. 027836492091048
Author(s):  
Mathieu Nowakowski ◽  
Cyril Joly ◽  
Sébastien Dalibard ◽  
Nicolas Garcia ◽  
Fabien Moutarde

This article introduces an indoor topological localization algorithm that uses vision and Wi-Fi signals. Its main contribution is a novel way of merging data from these sensors. The designed system does not require knowledge of the building plan or the positions of the Wi-Fi access points. By making the Wi-Fi signature suited to the FABMAP algorithm, this work develops an early fusion framework that solves global localization and kidnapped robot problems. The resulting algorithm has been tested and compared with FABMAP visual localization, over data acquired by a Pepper robot in three different environments: an office building, a middle school, and a private apartment. Numerous runs of different robots have been realized over several months for a total covered distance of 6.4 km. Constraints were applied during acquisitions to make the experiments fitted to real use cases of Pepper robots. Without any tuning, our early fusion framework outperforms visual localization in all testing situations and with a significant margin in environments where vision faces problems such as moving objects or perceptual aliasing. In such conditions, 90.6% of estimated localizations are less than 5 m away from ground truth with our early fusion framework compared with 77.6% with visual localization. Furthermore, compared with other classical fusion strategies, the early fusion framework produces the best localization results because in all tested situations, it improves visual localization results without damaging them where Wi-Fi signals carry little information.


2019 ◽  
Author(s):  
Tiffany K Weidner ◽  
John T Kidwell ◽  
David A Etzioni

Diverticulitis in certain subpopulations of patients may require different treatments, especially in the elective setting. Diverticular bleeding, another complication of diverticulosis, is another source of burden on United States healthcare from diverticular disease. This chapter discusses the special circumstances of right-sided diverticulitis, diverticulitis in young patients or immunocompromised patients, recurrent diverticulitis after resection, giant colonic diverticulum, and rare presentations of diverticulitis. Atypical types of diverticulitis such as segmental colitis associated with diverticulosis (SCAD), symptomatic uncomplicated diverticular disease (SUDD), and smoldering diverticulitis are also reviewed, and indications for surgical intervention are summarized. Current controversies are reviewed, including the decision to operate in young or immunocompromised patients; management of SCAD, SUDD, or smoldering diverticulitis; and best localization method to diagnose diverticular bleeding. This review contains 6 figures, 2 tables, and 55 references. Key Words: atypical diverticulitis, diverticular bleeding, diverticular disease, diverticulosis, gastrointestinal bleeding, right-sided diverticulitis, segmental colitis associated with diverticulosis, smoldering diverticulitis, symptomatic uncomplicated diverticular disease, total abdominal colectomy


2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Zhiyu Lu ◽  
Jianhui Wang ◽  
Bin Ba ◽  
Daming Wang

The existing localization algorithms for coherently distributed (CD) sources fail to achieve the best localization performance because of position information loss and error accumulation. To solve this problem, this study proposed a novel direct position determination (DPD) algorithm that profits from the characteristics of noncircular signals. Based on the parameterization assumption of CD sources, the DPD localization model is initially constructed and an extended subspace data fusion-based DPD algorithm is subsequently proposed by decomposing the extended covariance matrices, which are constructed by combining the characteristics of noncircular sources. The algorithm achieves a low complexity and a high efficiency by avoiding the calculation of the intermediate variables. Specifically, the closed-form expression of the Cramer-Rao lower bound for CD noncircular sources is also derived. Simulation results show that, compared with existing DPD algorithms, the proposed algorithm improves the multitarget localization capability and achieves high-accuracy results.


2018 ◽  
Vol 146 (2) ◽  
pp. 543-560 ◽  
Author(s):  
Yue Ying ◽  
Fuqing Zhang ◽  
Jeffrey L. Anderson

Covariance localization remedies sampling errors due to limited ensemble size in ensemble data assimilation. Previous studies suggest that the optimal localization radius depends on ensemble size, observation density and accuracy, as well as the correlation length scale determined by model dynamics. A comprehensive localization theory for multiscale dynamical systems with varying observation density remains an active area of research. Using a two-layer quasigeostrophic (QG) model, this study systematically evaluates the sensitivity of the best Gaspari–Cohn localization radius to changes in model resolution, ensemble size, and observing networks. Numerical experiment results show that the best localization radius is smaller for smaller-scale components of a QG flow, indicating its scale dependency. The best localization radius is rather insensitive to changes in model resolution, as long as the key dynamical processes are reasonably well represented by the low-resolution model with inflation methods that account for representation errors. As ensemble size decreases, the best localization radius shifts to smaller values. However, for nonlocal correlations between an observation and state variables that peak at a certain distance, decreasing localization radii further within this distance does not reduce analysis errors. Increasing the density of an observing network has two effects that both reduce the best localization radius. First, the reduced observation error spectral variance further constrains prior ensembles at large scales. Less large-scale contribution results in a shorter overall correlation length, which favors a smaller localization radius. Second, a denser network provides more independent pieces of information, thus a smaller localization radius still allows the same number of observations to constrain each state variable.


2007 ◽  
Vol 51 (8) ◽  
pp. 1217-1225 ◽  
Author(s):  
Andrea M. Isidori ◽  
Andrea Lenzi

Ectopic adrenocorticotropic secretion (EAS) is responsible for 12-17% of cases of Cushing's syndrome (CS) and covers a range of tumours, from undetectable benign lesions to widespread metastases. The syndrome is often associated with severe hypercortisolaemia, which aggravates the underlying condition. EAS requires a complete workup that includes the establishment of endogenous CS, diagnosis of adrenocorticotropic hormone (ACTH) dependency, localization of the source of ACTH secretion and rapid biochemical control of hypercortisolaemia. Dynamic endocrine tests should include inferior petrosal sinus sampling with CRH stimulation. Localization studies depend on the availability of reliable high-resolution cross-sectional imaging. This systematic review of the largest published series of patients with EAS (over 380 patients) reveals the common trends in the prevalence and management of this syndrome. The concept of 'occult' EAS has been revisited and the terms 'overt' and 'covert' EAS introduced. In addition to small cell lung carcinoma, the most common causes of ectopic EAS are bronchial carcinoids, thymic tumours, islet cell tumour of the pancreas, medullary thyroid carcinomas, and phaeochromocytomas. Their prevalence and the best localization modalities are presented. Medical and surgical management is discussed on the basis of the extensive experience of major referral centres.


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