scholarly journals Studying the Impact of Initialization for Population-Based Algorithms with Low-Discrepancy Sequences

2021 ◽  
Vol 11 (17) ◽  
pp. 8190
Author(s):  
Adnan Ashraf ◽  
Sobia Pervaiz ◽  
Waqas Haider Bangyal ◽  
Kashif Nisar ◽  
Ag. Asri Ag. Ibrahim ◽  
...  
Keyword(s):  
Heuristic Algorithms ◽  
Random Sequence ◽  
Search Space ◽  
Population Based ◽  
Test Problems ◽  
Low Discrepancy Sequences ◽  
Experimental Findings ◽  
Optimum Solution ◽  
The Impact

To solve different kinds of optimization challenges, meta-heuristic algorithms have been extensively used. Population initialization plays a prominent role in meta-heuristic algorithms for the problem of optimization. These algorithms can affect convergence to identify a robust optimum solution. To investigate the effectiveness of diversity, many scholars have a focus on the reliability and quality of meta-heuristic algorithms for enhancement. To initialize the population in the search space, this dissertation proposes three new low discrepancy sequences for population initialization instead of uniform distribution called the WELL sequence, Knuth sequence, and Torus sequence. This paper also introduces a detailed survey of the different initialization methods of PSO and DE based on quasi-random sequence families such as the Sobol sequence, Halton sequence, and uniform random distribution. For well-known benchmark test problems and learning of artificial neural network, the proposed methods for PSO (TO-PSO, KN-PSO, and WE-PSO), BA (BA-TO, BA-WE, and BA-KN), and DE (DE-TO, DE-WE, and DE-KN) have been evaluated. The synthesis of our strategies demonstrates promising success over uniform random numbers using low discrepancy sequences. The experimental findings indicate that the initialization based on low discrepancy sequences is exceptionally stronger than the uniform random number. Furthermore, our work outlines the profound effects on convergence and heterogeneity of the proposed methodology. It is expected that a comparative simulation survey of the low discrepancy sequence would be beneficial for the investigator to analyze the meta-heuristic algorithms in detail.

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 Blood Coagulation Algorithm: A Novel Bio-Inspired Meta-Heuristic Algorithm for Global Optimization

Mathematics ◽  
2021 ◽  
Vol 9 (23) ◽  
pp. 3011
Author(s):  
Drishti Yadav
Keyword(s):  
Blood Coagulation ◽  
Heuristic Algorithms ◽  
Cooperative Behavior ◽  
Real Life ◽  
Search Space ◽  
Population Based ◽  
Test Analysis ◽  
Search Spaces ◽  
Consistent Performance ◽  
The Comparative Study

This paper introduces a novel population-based bio-inspired meta-heuristic optimization algorithm, called Blood Coagulation Algorithm (BCA). BCA derives inspiration from the process of blood coagulation in the human body. The underlying concepts and ideas behind the proposed algorithm are the cooperative behavior of thrombocytes and their intelligent strategy of clot formation. These behaviors are modeled and utilized to underscore intensification and diversification in a given search space. A comparison with various state-of-the-art meta-heuristic algorithms over a test suite of 23 renowned benchmark functions reflects the efficiency of BCA. An extensive investigation is conducted to analyze the performance, convergence behavior and computational complexity of BCA. The comparative study and statistical test analysis demonstrate that BCA offers very competitive and statistically significant results compared to other eminent meta-heuristic algorithms. Experimental results also show the consistent performance of BCA in high dimensional search spaces. Furthermore, we demonstrate the applicability of BCA on real-world applications by solving several real-life engineering problems.

scholarly journals Driving Factors for the Utilisation of Healthcare Services by People with Osteoarthritis: Results from A Nationwide Population-Based study

2021 ◽  
Author(s):  
Daniela Costa ◽  
Ana M Rodrigues ◽  
Eduardo B Cruz ◽  
Helena Canhão ◽  
Jaime da Cunha Branco ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Multinomial Logistic Regression ◽  
Healthcare Utilisation ◽  
Healthcare Services ◽  
Structured Interview ◽  
Population Based ◽  
Enabling Factors ◽  
Population Based Study ◽  
The Impact

Abstract Background: Worldwide, the current management of knee osteoarthritis appears heterogeneous, high-cost and often not based on current best evidence. The absence of epidemiological data regarding the utilisation of healthcare services may conceal the need for improvements in the management of osteoarthritis. The aim of this study is to explore the profiles of healthcare services utilisation by people with knee osteoarthritis, and to analyse their determinants, according to Andersen’s behavioural model. Methods: We analysed a sample of 978 participants diagnosed with knee osteoarthritis from the population-based study EpiReumaPt . Data was collected with a structured interview, and the diagnosis of knee osteoarthritis was validated by a rheumatologist team. With the Two-step Cluster procedure, we primarily identified different profiles of healthcare utilisation according to the services most used by patients with knee osteoarthritis. Secondly, we analysed the determinants of each profile, using multinomial logistic regression, according to the predisposing characteristics, enabling factors and need variables.Results: In our sample, a high proportion of participants are overweight or obese (82,6%, n=748) and physically inactive (20,6%, n=201) and a small proportion had physiotherapy management (14,4%, n=141). We identified three profiles of healthcare utilisation: “HighUsers”; “GPUsers”; “LowUsers”. “HighUsers” represents more than 35% of the sample, and are also the participants with higher utilisation of medical appointments. "GPUsers" represent the participants with higher utilisation of general practitioner appointments. Within these profiles, age and geographic location – indicated as predisposing characteristics; employment status and healthcare insurance - as enabling factors; number of comorbidities, physical function, health-related quality of life, anxiety and physical exercise - as need variables, showed associations ( p <0,05) with the higher utilisation of healthcare services profiles. Conclusions: Healthcare utilisation by people with knee osteoarthritis is not driven only by clinical needs. The predisposing characteristics and enabling factors associated with healthcare utilisation reveal inequities in the access to healthcare and variability in the management of people with knee osteoarthritis. Research and implementation of whole-system strategies to improve equity in the access and quality of care are paramount in order to diminish the impact of osteoarthritis at individual-, societal- and economic-level.

scholarly journals Relationship between dental fluorosis and quality of life: a population based study

2005 ◽  
Vol 19 (2) ◽  
pp. 150-155 ◽  
Author(s):  
Edgard Michel-Crosato ◽  
Maria Gabriela Haye Biazevic ◽  
Edgard Crosato
Keyword(s):  
Quality Of Life ◽  
Water Supply ◽  
Dental Fluorosis ◽  
Female Gender ◽  
Population Based ◽  
Daily Activities ◽  
Cross Sectional ◽  
Significance Level ◽  
The Impact

The aim of this study was to verify the prevalence of dental fluorosis in schoolchildren aged 6 to 15 and its possible association with the impacts on their daily activities. This study is observational, cross-sectional and analytical. A total of 513 schoolchildren from the city of Pinheiro Preto, SC, took part in this study. The children were examined by three calibrated dentists, after obtaining a kappa > 0.80. To assess the prevalence of fluorosis, clinical examinations were performed according to the methodology set forth by the 4th edition of the WHO. To assess the impact of fluorosis on their daily activities, a modified OIDP (Oral Impacts on Daily Performance) was adopted. The statistical analysis used was the Chi-squared test with a 5% significance level. Of the total number of children examined, 262 (51.1%) were of the female gender and 251 (48.9%) were of the male gender. In regard to the prevalence of fluorosis, 94 (18.3%) of the children presented this condition, while 419 children (81.7%) presented a normal condition. In regard to the severity of fluorosis, few children presented severe alterations. No association was found between dental fluorosis and gender (p = 0.646), between fluorosis and socioeconomic status (p = 0.848) or between fluorosis and access to public water supply system (p = 0.198). The activities that most affected children's daily performance were: oral hygiene (40.9%) and food intake or enjoying food (40.4%). None of the daily activities could be associated with the occurrence of dental fluorosis. The prevalence of dental fluorosis was consonant with the standards found for locations with optimum fluoride content in the water supply. The questionable and very slight levels of fluorosis were the most frequently found, without influence in the quality of life of the schoolchildren participating in the study.

scholarly journals Brain atlas for assessing the impact of tumor location on perioperative quality of life in patients with high-grade glioma: A prospective population-based cohort study

2019 ◽  
Vol 21 ◽  
pp. 101658 ◽  
Author(s):  
Lisa Millgård Sagberg ◽  
Daniel Høyer Iversen ◽  
Even Hovig Fyllingen ◽  
Asgeir Store Jakola ◽  
Ingerid Reinertsen ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Cohort Study ◽  
High Grade Glioma ◽  
Tumor Location ◽  
Population Based ◽  
Brain Atlas ◽  
High Grade ◽  
The Impact

Parallel Scatter Search Algorithms for Exam Timetabling

2011 ◽  
Vol 2 (3) ◽  
pp. 27-44 ◽  
Author(s):  
Nashat Mansour ◽  
Ghia Sleiman-Haidar
Keyword(s):  
Heuristic Algorithms ◽  
Scatter Search ◽  
Search Space ◽  
Population Based ◽  
Search Algorithms ◽  
Sequential Algorithm ◽  
Solution Quality ◽  
Reasonable Time ◽  
Exam Timetabling ◽  
Communication Techniques

University exam timetabling refers to scheduling exams into predefined days, time periods and rooms, given a set of constraints. Exam timetabling is a computationally intractable optimization problem, which requires heuristic techniques for producing adequate solutions within reasonable execution time. For large numbers of exams and students, sequential algorithms are likely to be time consuming. This paper presents parallel scatter search meta-heuristic algorithms for producing good sub-optimal exam timetables in a reasonable time. Scatter search is a population-based approach that generates solutions over a number of iterations and aims to combine diversification and search intensification. The authors propose parallel scatter search algorithms that are based on distributing the population of candidate solutions over a number of processors in a PC cluster environment. The main components of scatter search are computed in parallel and efficient communication techniques are employed. Empirical results show that the proposed parallel scatter search algorithms yield good speed-up. Also, they show that parallel scatter search algorithms improve solution quality because they explore larger parts of the search space within reasonable time, in contrast with the sequential algorithm.

A FAST HYBRID ALGORITHM FOR MULTICAST ROUTING IN WIRELESS NETWORKS

2007 ◽  
Vol 16 (01) ◽  
pp. 45-68 ◽  
Author(s):  
S. AL-SHARHAN ◽  
W. GUEAIEB
Keyword(s):  
Wireless Networks ◽  
Hybrid Algorithm ◽  
Heuristic Algorithms ◽  
Multicast Routing ◽  
Learning Algorithm ◽  
Population Based ◽  
Multicast Tree ◽  
Recent Developments ◽  
Real Challenge

This paper tackles the issue of constrained multicast routing in wireless networks using a hybrid soft computing-based algorithm. Recent developments in multimedia applications and the dynamic and rapidly changed environment of the wireless networks make the constrained multicast routing a real challenge. The problem can be formulated as minimizing a multicast tree cost under several constraints or Quality of Service (QoS) metrics. This problem has been proven to be NP-complete. The proposed hybrid algorithm is based on a population based incremental learning algorithm that combines in an efficient way the features of genetic algorithms and competitive learning. Experimental results show that, in most cases, the proposed algorithm yields better solutions than other heuristic algorithms proposed in the literature.

scholarly journals Comparative Analysis of Low Discrepancy Sequence-Based Initialization Approaches Using Population-Based Algorithms for Solving the Global Optimization Problems

2021 ◽  
Vol 11 (16) ◽  
pp. 7591
Author(s):  
Waqas Haider Bangyal ◽  
Kashif Nisar ◽  
Ag. Asri Bin Ag. Ibrahim ◽  
Muhammad Reazul Haque ◽  
Joel J. P. C. Rodrigues ◽  
...  
Keyword(s):  
Random Distribution ◽  
Random Number ◽  
Optimization Problems ◽  
Optimal Solution ◽  
Search Space ◽  
Metaheuristic Algorithms ◽  
Test Problems ◽  
Uniform Random Number ◽  
Low Discrepancy Sequences ◽  
The Family

Metaheuristic algorithms have been widely used to solve diverse kinds of optimization problems. For an optimization problem, population initialization plays a significant role in metaheuristic algorithms. These algorithms can influence the convergence to find an efficient optimal solution. Mainly, for recognizing the importance of diversity, several researchers have worked on the performance for the improvement of metaheuristic algorithms. Population initialization is a vital factor in metaheuristic algorithms such as PSO and DE. Instead of applying the random distribution for the initialization of the population, quasirandom sequences are more useful for the improvement the diversity and convergence factors. This study presents three new low-discrepancy sequences named WELL sequence, Knuth sequence, and Torus sequence to initialize the population in the search space. This paper also gives a comprehensive survey of the various PSO and DE initialization approaches based on the family of quasirandom sequences such as Sobol sequence, Halton sequence, and uniform random distribution. The proposed methods for PSO (TO-PSO, KN-PSO, and WE-PSO) and DE (DE-TO, DE-WE, and DE-KN) have been examined for well-known benchmark test problems and training of the artificial neural network. The finding of our techniques shows promising performance using the family of low-discrepancy sequences over uniform random numbers. For a fair comparison, the approaches using low-discrepancy sequences for PSO and DE are compared with the other family of low-discrepancy sequences and uniform random number and depict the superior results. The experimental results show that the low-discrepancy sequences-based initialization performed exceptionally better than a uniform random number. Moreover, the outcome of our work presents a foresight on how the proposed technique profoundly impacts convergence and diversity. It is anticipated that this low-discrepancy sequence comparative simulation survey would be helpful for studying the metaheuristic algorithm in detail for the researcher.

scholarly journals Driving factors for the utilisation of healthcare services by people with osteoarthritis in Portugal: results from a nationwide population-based study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Daniela Costa ◽  
Ana M. Rodrigues ◽  
Eduardo B. Cruz ◽  
Helena Canhão ◽  
Jaime Branco ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Multinomial Logistic Regression ◽  
Healthcare Utilisation ◽  
Healthcare Services ◽  
Structured Interview ◽  
Population Based ◽  
Enabling Factors ◽  
Population Based Study ◽  
The Impact

Abstract Background Worldwide, the current management of knee osteoarthritis appears heterogeneous, high-cost and often not based on current best evidence. The absence of epidemiological data regarding the utilisation of healthcare services may conceal the need for improvements in the management of osteoarthritis. The aim of this study is to explore the profiles of healthcare services utilisation by people with knee osteoarthritis, and to analyse their determinants, according to Andersen’s behavioural model. Methods We analysed a sample of 978 participants diagnosed with knee osteoarthritis from the population-based study EpiReumaPt, in Portugal. Data was collected with a structured interview, and the diagnosis of knee osteoarthritis was validated by a rheumatologist team. With the Two-step Cluster procedure, we primarily identified different profiles of healthcare utilisation according to the services most used by patients with knee osteoarthritis. Secondly, we analysed the determinants of each profile, using multinomial logistic regression, according to the predisposing characteristics, enabling factors and need variables. Results In our sample, a high proportion of participants are overweight or obese (82,6%, n = 748) and physically inactive (20,6%, n = 201) and a small proportion had physiotherapy management (14,4%, n = 141). We identified three profiles of healthcare utilisation: “HighUsers”; “GPUsers”; “LowUsers”. “HighUsers” represents more than 35% of the sample, and are also the participants with higher utilisation of medical appointments. “GPUsers” represent the participants with higher utilisation of general practitioner appointments. Within these profiles, age and geographic location – indicated as predisposing characteristics; employment status and healthcare insurance - as enabling factors; number of comorbidities, physical function, health-related quality of life, anxiety and physical exercise - as need variables, showed associations (p < 0,05) with the higher utilisation of healthcare services profiles. Conclusions Healthcare utilisation by people with knee osteoarthritis is not driven only by clinical needs. The predisposing characteristics and enabling factors associated with healthcare utilisation reveal inequities in the access to healthcare and variability in the management of people with knee osteoarthritis. Research and implementation of whole-system strategies to improve equity in the access and quality of care are paramount in order to diminish the impact of osteoarthritis at individual-, societal- and economic-level.

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