scholarly journals Improved Method for Parallelization of Evolutionary Metaheuristics

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1476
Author(s):  
Diego Díaz ◽  
Pablo Valledor ◽  
Borja Ena ◽  
Miguel Iglesias ◽  
César Menéndez
Keyword(s):  
Propagation Rate ◽  
Population Based ◽  
New Method ◽  
Benchmark Problems ◽  
Main Concept ◽  
Traveling Salesman Problems ◽  
Solution Quality ◽  
Complex Design ◽  
Naive Approach

This paper introduces a method for the distribution of any and all population-based metaheuristics. It improves on the naive approach, independent multiple runs, while adding negligible overhead. Existing methods that coordinate instances across a cluster typically require some compromise of more complex design, higher communication loads, and solution propagation rate, requiring more work to develop and more resources to run. The aim of the new method is not to achieve state-of-the-art results, but rather to provide a better baseline method than multiple independent runs. The main concept of the method is that one of the instances receives updates with the current best solution of all other instances. This work describes the general approach and its particularization to both genetic algorithms and ant colony optimization for solving Traveling Salesman Problems (TSPs). It also includes extensive tests on the TSPLIB benchmark problems of resulting quality of the solutions and anytime performance (solution quality versus time to reach it). These tests show that the new method yields better solutions for about two thirds of the problems and equivalent solutions in the remaining third, and consistently exhibits better anytime performance.

scholarly journals Chaotic Jaya Approaches to Solving Electromagnetic Optimization Benchmark Problems

Telecom ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 222-231
Author(s):  
Leandro dos S. Coelho ◽  
Viviana C. Mariani ◽  
Sotirios K. Goudos ◽  
Achilles D. Boursianis ◽  
Konstantinos Kokkinidis ◽  
...  
Keyword(s):  
Optimization Problems ◽  
Population Based ◽  
Benchmark Problems ◽  
Jaya Algorithm ◽  
Solution Quality ◽  
Chaotic Mapping ◽  
Logistic Mapping ◽  
Essential Idea ◽  
Convergence Performance ◽  
Application Fields

The Jaya optimization algorithm is a simple, fast, robust, and powerful population-based stochastic metaheuristic that in recent years has been successfully applied in a variety of global optimization problems in various application fields. The essential idea of the Jaya algorithm is that the searching agents try to change their positions toward the best obtained solution by avoiding the worst solution at every generation. The important difference between Jaya and other metaheuristics is that Jaya does not require the tuning of its control, except for the maximum number of iterations and population size parameters. However, like other metaheuristics, Jaya still has the dilemma of an appropriate tradeoff between its exploration and exploitation abilities during the evolution process. To enhance the convergence performance of the standard Jaya algorithm in the continuous domain, chaotic Jaya (CJ) frameworks based on chaotic sequences are proposed in this paper. In order to obtain the performance of the standard Jaya and CJ approaches, tests related to electromagnetic optimization using two different benchmark problems are conducted. These are the Loney’s solenoid benchmark and a brushless direct current (DC) motor benchmark. Both problems are realized to evaluate the effectiveness and convergence rate. The simulation results and comparisons with the standard Jaya algorithm demonstrated that the performance of the CJ approaches based on Chebyshev-type chaotic mapping and logistic mapping can be competitive results in terms of both efficiency and solution quality in electromagnetics optimization.

Assessing the quality of public health in the Russian Federation and Israel: Main problems and solutions

2020 ◽  
Vol 19 (4) ◽  
pp. 618-632
Author(s):  
A.S. Panchenko
Keyword(s):  
Public Health ◽  
Russian Federation ◽  
Population Based ◽  
The Public ◽  
Disability Adjusted Life ◽  
Problems And Solutions ◽  
The Russian Federation ◽  
Disability Adjusted Life Year ◽  
Practical Recommendations

Subject. The article addresses the public health in the Russian Federation and Israel. Objectives. The focus is on researching the state of public health in Russia and Israel, using the Global Burden of Disease (GBD) project methodology, identifying problem areas and searching for possible ways to improve the quality of health of the Russian population based on the experience of Israel. Methods. The study draws on the ideology of the GBD project, which is based on the Disability-Adjusted Life-Year (DALY) metric. Results. The paper reveals the main causes of DALY losses and important risk factors for cancer for Russia and Israel. The findings show that the total DALY losses for Russia exceed Israeli values. The same is true for cancer diseases. Conclusions. Activities in Israel aimed at improving the quality of public health, the effectiveness of which has been proven, can serve as practical recommendations for Russia. The method of analysis, using the ideology of the GBD project, can be used as a tool for quantitative and comparative assessment of the public health.

UGR CALCULATION BASED ON THE LUMINANCE SPATIAL-ANGULAR DISTRIBUTION

2020 ◽  
Vol 2020 (4) ◽  
pp. 25-32
Author(s):  
Viktor Zheltov ◽  
Viktor Chembaev
Keyword(s):  
Monte Carlo ◽  
Angular Distribution ◽  
Monte Carlo Method ◽  
Visual Task ◽  
New Method ◽  
Lighting System ◽  
Preliminary Assessment ◽  
System A ◽  
The Monte Carlo Method

The article has considered the calculation of the unified glare rating (UGR) based on the luminance spatial-angular distribution (LSAD). The method of local estimations of the Monte Carlo method is proposed as a method for modeling LSAD. On the basis of LSAD, it becomes possible to evaluate the quality of lighting by many criteria, including the generally accepted UGR. UGR allows preliminary assessment of the level of comfort for performing a visual task in a lighting system. A new method of "pixel-by-pixel" calculation of UGR based on LSAD is proposed.

scholarly journals Population-based rapid assessment of avoidable blindness survey in Sohag governorate in Egypt

BMJ Open ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. e036337
Author(s):  
Heba AlSawahli ◽  
Ian McCormick ◽  
Caleb D Mpyet ◽  
Gamal Ezzelarab ◽  
Mohammad Shalaby
Keyword(s):  
Cataract Surgery ◽  
Census Data ◽  
Rapid Assessment ◽  
Population Based ◽  
Vision Impairment ◽  
Health System Strengthening ◽  
Secondary Outcome ◽  
Institutional Setting ◽  
Financial Barriers

ObjectivesTo determine the prevalence and causes of blindness and vision impairment, and the coverage and quality of cataract surgical services, among population aged 50 years and older in Sohag governorate in Egypt.DesignA population-based cross-sectional survey using two-stage cluster random sampling following the rapid assessment of avoidable blindness methodology.SettingA community-based survey conducted by six teams of ophthalmologists, assistants and local guides. Enrolment and examination were door-to-door in selected clusters.ParticipantsUsing 2016 census data, 68 population units were randomly selected as clusters (of 60 people) with probability proportionate to population size. Anyone aged 50 years and older, residing in a non-institutional setting in a cluster for at least 6 months, was eligible to participate.Primary and secondary outcome measuresThe prevalence and causes of blindness and vision impairment. Secondary outcomes were CSC and effectiveness and participant-reported barriers to cataract surgery.ResultsOf 4078 participants enrolled, 4033 (98.9%) were examined. The age-adjusted and sex-adjusted prevalence of blindness, severe vision impairment and moderate vision impairment were 5.9% (95% CI 4.8% to 6.9%), 4.7% (95% CI 3.8% to 5.7%) and 18.9% (95% CI 16.8% to 21.0%), respectively. Cataract caused most of blindness (41.6%), followed by non-trachomatous corneal opacity (15.7%) and posterior segment diseases (14.5%). Cataract surgical coverage (CSC) for persons for visual acuity <3/60 was 86.8%, the proportion of cataract surgeries with poor visual outcome was 29.5% and effective CSC (eCSC) was 44.9%. eCSC was lower in women than men. The most frequently reported barrier to surgery was cost (51.5%).ConclusionsThe prevalence of blindness in Sohag governorate is higher than districts in other middle-income countries in the region. CSC was high; however, women suffer worse quality-corrected CSC than men. The quality of cataract surgery needs to be addressed, while health system strengthening across government and private settings could alleviate financial barriers.

scholarly journals Quality of life among people living with HIV in England and the Netherlands: a population-based study

2021 ◽  
Vol 8 ◽  
pp. 100177
Author(s):  
Stephanie Popping ◽  
Meaghan Kall ◽  
Brooke E. Nichols ◽  
Evelien Stempher ◽  
Lisbeth Versteegh ◽  
...  
Keyword(s):  
Quality Of Life ◽  
The Netherlands ◽  
Population Based ◽  
People Living With Hiv ◽  
Population Based Study ◽  
Living With Hiv

Primary care and suicidality among psychiatric outpatients: The patient-doctor relationship matters

2020 ◽  
pp. 009121742097799
Author(s):  
Krista Schultz ◽  
Sharan Sandhu ◽  
David Kealy
Keyword(s):  
Mental Health ◽  
Primary Care ◽  
Borderline Personality Disorder ◽  
Personality Disorder ◽  
Primary Care Physician ◽  
Population Based ◽  
Borderline Personality ◽  
Care Physician ◽  
Cross Sectional

Objective The purpose of the current study is to examine the relationship between the quality of the Patient-Doctor Relationship and suicidality among patients seeking mental health care; specifically, whether patients who perceive having a more positive relationship with primary care physician will have lower levels of suicidality. Method Cross-sectional population-based study in Greater Vancouver, Canada. One-hundred ninety-seven participants were recruited from three Mental Health Clinics who reported having a primary care physician. Participants completed a survey containing questions regarding items assessing quality of Patient-Doctor Relationship, general psychiatric distress (K10), borderline personality disorder, and suicidality (Suicidal Behaviours Questionnaire-Revised-SBQ-R). Zero-order correlations were computed to evaluate relationships between study variables. Hierarchical regression analysis was used to control for confounding variables. Results The quality of the patient doctor relationship was significantly negatively associated with suicidality. The association between the quality of the patient-doctor relationship and suicidality remained significant even after controlling for the effects of psychiatric symptom distress and borderline personality disorder features. Conclusions The degree to which patients’ perceive their primary care physician as understanding, reliable, and dedicated, is associated with a reduction in suicidal behaviors. Further research is needed to better explicate the mechanisms of this relationship over time.

scholarly journals Modelling the impacts of COVID-19 pandemic on the quality of population-based colorectal cancer screening

2021 ◽  
Vol 151 ◽  
pp. 106597
Author(s):  
Grace Hsiao-Hsuan Jen ◽  
Amy Ming-Fang Yen ◽  
Chen-Yang Hsu ◽  
Han-Mo Chiu ◽  
Sam Li-Sheng Chen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Screening ◽  
Colorectal Cancer Screening ◽  
Population Based

scholarly journals Prevalence of nocturia among community-dwelling adults: a population-based study in Malaysia

BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hui-Yin Yow ◽  
John Jeh Lung Tiong ◽  
Chun-Wai Mai ◽  
Esther van der Werf ◽  
Zulkifli Md Zainuddin ◽  
...  
Keyword(s):  
Medical Condition ◽  
Population Based ◽  
Community Dwelling ◽  
Medical Attention ◽  
Night Time ◽  
Cross Sectional ◽  
Population Based Study ◽  
Waking Up ◽  
The Impact

Abstract Background Nocturia is widely prevalent condition with detrimental effects on quality of life and general health. In Malaysia, there is a lack of up-to-date prevalence study on nocturia. This study aimed to investigate the prevalence of nocturia and awareness pertaining to nocturia among Malaysian adults. Methods A cross-sectional population-based study was conducted among Malaysian adults aged ≥ 18 years old. The data was collected by mixed mode self-administered questionnaire from May 2019 to September 2019. Nocturia was defined as one or more voids at night. Results There were a total of 4616 respondents with 74.5% of response rate. The overall prevalence of nocturia among Malaysian adults was found to be 57.3%. In multivariate analysis, respondents aged 31–40 (1.91 [1.52–2.40]) or > 60 years old (2.03 [1.48–2.71]), and those who presented with hypertension (2.84 [2.28–3.53]), diabetes mellitus (1.78 [1.42–2.25]), renal disease (3.58 [1.93–6.63]) or overactive bladder (1.61 [1.10–2.35]) were associated with higher prevalence of nocturia. A significantly lower disease prevalence (p < 0.05) was noted among those aged 41–50 (0.73 [0.59–0.91]), male (0.78 [0.69–0.88]) and Chinese (0.47 [0.30–0.74]) or Indian (0.34 [0.21–0.54]) ethnicities. A total of 37.3% of respondents with nocturia reported that they faced sleeping difficulty about half the time or more after waking up in the middle of night. Those who had ≥ 2 voids per night experienced significantly higher mean bother score than those who had 1 void per night (p < 0.001). Approximately half (56.7%) of all respondents were not aware that night time urination is a medical condition. Only 25.2% of respondents with nocturia had sought medical attention for their nocturia. Conclusions The prevalence of nocturia among Malaysian adults is high and strongly influenced by age, sex, race and comorbidities. However, the general awareness pertaining to nocturia being a health issue remains low among Malaysians. The findings also highlighted the impact of nocturia on sleep and the need for nocturia education to better address this disease.

scholarly journals On Examining the Quality of Spanish Translation in Telephone Surveys: A Novel Test-Retest Approach

2019 ◽  
Vol 8 (4) ◽  
pp. 691-705
Author(s):  
Robert P Agans ◽  
Quirina M Vallejos ◽  
Thad S Benefield
Keyword(s):  
Past Research ◽  
Population Based ◽  
Pilot Test ◽  
Spanish Translation ◽  
Convenience Sample ◽  
Single Item ◽  
Telephone Surveys ◽  
Survey Questions ◽  
Health Related

Abstract Past research has shown that commonly reported cultural group disparities in health-related indices may be attributable to culturally mediated differences in the interpretation of translated survey questions and response scales. This problem may be exacerbated when administering single-item survey questions, which typically lack the reliability seen in multi-item scales. We adapt the test-retest approach for single-item survey questions that have been translated from English into Spanish and demonstrate how to use this approach as a quick and efficient pilot test before fielding a major survey. Three retest conditions were implemented (English-Spanish, Spanish-English, and English-English) on a convenience sample (n = 109) of Latinos and non-Latinos where translated items were compared against an English-English condition that served as our control. Several items were flagged for investigation using this approach. Discussion centers on the utility of this approach for evaluating the Spanish translation of single-item questions in population-based surveys.

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