scholarly journals GIS-Based Kernel Analysis for Tourism Flow Mapping

2020 ◽  
Vol 11 (2) ◽  
pp. 137-145
Author(s):  
Mărgărit-Mircea NISTOR ◽  
Alexandru-Sabin NICULA ◽  
Ştefan DEZSI ◽  
Dănuţ PETREA ◽  
Shankar Acharya KAMARAJUGEDDA ◽  
...  

The variation of tourism flow and its spatial representation are indispensable for transport companies, accommodation facilities and future estimations regarding the international arrivals. The major implication for tourism flow mapping is related to the country of origin of tourists, their liquid assets, and tourism statistical database. The approach of tourism flow mapping representation, at least using lines and density, should be based on the spatial characteristics of the objects. In this study, the database consisting of international arrivals in different cities of Romania was used as an example. Thus, GIS-based Kernel density of the tourists’ flow was proposed. To illustrate the international demand, data on arrivals for 33 countries over the period 2015-2017 were used. ‘XY To Line’ and ‘Kernel Density’ functions served to create the convergence lines between the origin countries and Romania. The very high density was found for the European countries with an increase of 13% and 25% between 2015 and 2016, as well as between 2015 and 2017. Map analysis indicated an increase of the density area by 0.7% for 2016 and 1.7% for 2017. The proposed methods, including lines and density, contribute to the mapping of the flow of the international arrivals in Romania.

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K.K Ray ◽  
S Bray ◽  
A.L Catapano ◽  
N Poulter ◽  
G Villa

Abstract Background/Introduction For patients at very-high risk of cardiovascular (CV) events, the 2016 ESC/EAS dyslipidaemia guidelines recommended lipid-lowering therapy (LLT) to achieve an LDL-C level below 70 mg/dL. This was lowered to an LDL-C level below 55 mg/dL in the 2019 guidelines. Purpose To assess: 1) the risk profile of European patients with established atherosclerotic CV disease (ASCVD) receiving LLT; and 2) the treatment gap between the estimated risk and the population benefits if all patients were to achieve LDL-C levels of 70 mg/dL and 55 mg/dL. Methods We used data from Da Vinci, an observational cross-sectional study conducted across 18 European countries. Data were collected at a single visit between June 2017 and November 2018, for consented adults who had received any LLT in the prior 12 months and had an LDL-C measurement in the prior 14 months. LDL-C level was assessed at least 28 days after starting the most recent LLT (stabilised LLT). For each patient with established ASCVD receiving stabilised LLT, we: 1) calculated their absolute LDL-C reduction required to achieve LDL-C levels of 70 mg/dL and 55 mg/dL; 2) predicted their 10-year CV risk using the REACH score based on demographic and medical history; 3) simulated their relative risk reduction (RRR) by randomly sampling from the probability distribution of the rate ratio per 38.7 mg/dL (1 mmol/L) estimated by the Cholesterol Treatment Trialists Collaboration meta-analysis; and 4) calculated their absolute risk reduction (ARR) achieved by meeting LDL-C levels of 70 mg/dL and 55 mg/dL. Results A total of 2039 patients with established ASCVD were included in the analysis. Mean (SD) LDL-C was 83.1 (35.2) mg/dL. 40.4% and 19.3% of patients achieved LDL-C levels of 70 mg/dL and 55 mg/dL, respectively. Mean (SD) 10-year CV risk calculated using the REACH score was 36.3% (15.4%). Mean absolute LDL-C reductions of 19.6 mg/dL and 30.4 mg/dL were needed to reach LDL-C levels of 70 mg/dL and 55 mg/dL, respectively. When adjusted for the LDL-C reduction required to achieve an LDL-C level of 70 mg/dL, mean ARR was 3.0%, leaving a mean (SD) residual 10-year CV risk of 33.3% (15.5%). When adjusted for the LDL-C reduction required to achieve an LDL-C level of 55 mg/dL, mean ARR was 4.6%, leaving a mean (SD) residual 10-year CV risk of 31.7% (15.2%). Conclusion(s) In a contemporary European cohort with ASCVD receiving LLT, the 10-year risk of CV events is high and many patients do not achieve LDL-C levels of 55 mg/dL or even of 70 mg/dL. Moreover, even if all patients were to achieve recommended LDL-C levels, they would still remain at a high residual risk of CV events. These data suggest these patients require even more intensive LLT. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Amgen


2016 ◽  
Vol 91 (1-2) ◽  
pp. 141-159 ◽  
Author(s):  
Arthur Charpentier ◽  
Emmanuel Flachaire

Standard kernel density estimation methods are very often used in practice to estimate density functions. It works well in numerous cases. However, it is known not to work so well with skewed, multimodal and heavy-tailed distributions. Such features are usual with income distributions, defined over the positive support. In this paper, we show that a preliminary logarithmic transformation of the data, combined with standard kernel density estimation methods, can provide a much better fit of the density estimation.


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 873
Author(s):  
Jinxin Wang ◽  
Chi Zhang ◽  
Xiuzhen Ma ◽  
Zhongwei Wang ◽  
Yuandong Xu ◽  
...  

The problem of timely detecting the engine faults that make engine operating parameters exceed their control limits has been well-solved. However, in practice, a fault of a diesel engine can be present with weak signatures, with the parameters fluctuating within their control limits when the fault occurs. The weak signatures of engine faults bring considerable difficulties to the effective condition monitoring of diesel engines. In this paper, a multivariate statistics-based fault detection approach is proposed to monitor engine faults with weak signatures by taking the correlation of various parameters into consideration. This approach firstly uses principal component analysis (PCA) to project the engine observations into a principal component subspace (PCS) and a residual subspace (RS). Two statistics, i.e., Hotelling’s T 2 and Q statistics, are then introduced to detect deviations in the PCS and the RS, respectively. The Hotelling’s T 2 and Q statistics are constructed by taking the correlation of various parameters into consideration, so that faults with weak signatures can be effectively detected via these two statistics. In order to reasonably determine the control limits of the statistics, adaptive kernel density estimation (KDE) is utilized to estimate the probability density functions (PDFs) of Hotelling’s T 2 and Q statistics. The control limits are accordingly derived from the PDFs by giving a desired confidence level. The proposed approach is demonstrated by using a marine diesel engine. Experimental results show that the proposed approach can effectively detect engine faults with weak signatures.


2011 ◽  
Vol 17 (2) ◽  
pp. 153-169 ◽  
Author(s):  
Zoltán Fazekas

Previous research has found that the presence of a union at a workplace is an important individual-level determinant of union membership. The present article, drawing on a multilevel analysis of 21 European countries, provides further evidence which nuances the conclusions of previous studies by introducing and testing institutional moderation effects. Thus, in countries with Ghent systems, having a union at workplace is less important, since probability of membership is already very high. Conversely, if there are extension mechanisms for collective agreements there is less incentive to join a trade union, and this is not compensated even when there is an active union at the workplace.


2019 ◽  
Vol 258 (3) ◽  
pp. 503-511
Author(s):  
Tomas Bro ◽  
Magdalena Derebecka ◽  
Øystein Kalsnes Jørstad ◽  
Andrzej Grzybowski

Abstract Purpose To analyse current off-label use of bevacizumab for wet age-related macular degeneration (AMD) in Europe. Methods The study was conducted as a combined survey and literature review. It included the 22 most populous countries in Europe. In each country, ophthalmologists with particular knowledge about off-label treatment responded to a questionnaire. Results Answers were obtained from twenty European countries. The off-label use of bevacizumab for wet AMD greatly differed between nations; the bevacizumab proportion varied from non-existent (0%) to very high (97%). There were also large disparities within single countries (e.g. 0–80%), which were attributable to differences in regional decision-making. Both governmental institutions and national ophthalmological societies expressed highly diverging opinions on the use of off-label treatment. Intravitreal administration of bevacizumab had been a matter of legal dispute in several countries. The question about responsibility for off-label therapy mainly remained unanswered. Conclusions There was a highly varying utilization of bevacizumab between European countries. Despite an intention of a consistent approach to medical regulations, Europe has not yet reached a professional or political consensus on the ophthalmic off-label use of bevacizumab.


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