Experimental Analysis of Search-Based Selection of Sample Points for Straightness and Flatness Estimation

2005 ◽  
Vol 127 (1) ◽  
pp. 96-103 ◽  
Author(s):  
M. Affan Badar ◽  
Shivakumar Raman ◽  
P. Simin Pulat ◽  
Randa L. Shehab
Keyword(s):  
Experimental Analysis ◽  
Manufacturing Process ◽  
Adaptive Sampling ◽  
Least Squares Method ◽  
Search Algorithm ◽  
Large Population ◽  
Population Sample ◽  
Step Size ◽  
Factor C ◽  
Optimization Search

In earlier work [Bader et al., ASME J. Manuf. Sci. Eng. 125(2), pp. 263–271 (2003); Int. J. Mach. Tools Manuf. 45(1), pp. 63–75 (2005)] the authors have presented an adaptive sampling method utilizing manufacturing error patterns and optimization search techniques for straightness and flatness evaluation. The least squares method was used to compute a tolerance zone. In this paper, experimental analysis is performed to verify the sturdiness of the adaptive sampling procedure. Experiments are carried out to investigate the effects of different factors on the sample size and absolute percent error of the estimated tolerance from that of a large population sample. Twelve 7075-T6 aluminum plates are end-milled and 12 cast iron plates are face-milled. Two sets of four plates from each lot are selected randomly, one each for straightness and flatness estimation. Factor A used in both straightness and flatness analyses is manufacturing process (i.e., surface error profile). Factor B for straightness is step size whereas for flatness it is search strategy (i.e., number of bad moves and restart allowed). Factor C for flatness is search algorithm (i.e., tabu and hybrid). Plates are nested within the levels of manufacturing process. The results have been analyzed and compared with other sampling methods. The analyses reveal that the current approach is more efficient and reliable.

scholarly journals Research on Maritime Emergency Material Dispatch Based on Beetle Antennae Search Algorithm

2021 ◽  
Vol 257 ◽  
pp. 03028
Author(s):  
Hongzheng Jiang ◽  
Yuzhu Zhu
Keyword(s):  
Search Algorithm ◽  
Variable Step Size ◽  
Optimization Scheme ◽  
Step Size ◽  
Material Supply ◽  
Scheduling Model ◽  
Variable Step ◽  
Use Efficiency ◽  
Optimal Material ◽  
Optimization Search

The research on dispatching of emergency supplies for maritime emergencies is the key to improve the use efficiency of marine emergency resources and the success rate of search and rescue. In view of the characteristics of emergency accidents at sea, in this paper, a material scheduling model with the shortest time is built for multi-accident points, multi-ship dispatching and multi-material supply points, and the optimal material scheduling scheme is obtained. The step-size updating coefficient eta is introduced into the variable step-size optimization search algorithm ( BAS ), so that the step-size decreases with the depth of optimization, which improves the searching precision and accuracy of the search algorithm. The simulation experiment verifies that this algorithm can solve the optimization scheme of material scheduling quickly and efficiently.

EXPRESS: Baseline Correction Based on a Search Algorithm from Artificial Intelligence

2020 ◽  
pp. 000370282097751
Author(s):  
Xin Wang ◽  
Xia Chen
Keyword(s):  
Artificial Intelligence ◽  
Objective Function ◽  
Least Squares ◽  
Least Squares Method ◽  
Search Algorithm ◽  
Absolute Error ◽  
Search Problem ◽  
Baseline Correction ◽  
Current Spectrum ◽  
Data Points

Many spectra have a polynomial-like baseline. Iterative polynomial fitting (IPF) is one of the most popular methods for baseline correction of these spectra. However, the baseline estimated by IPF may have substantially error when the spectrum contains significantly strong peaks or have strong peaks located at the endpoints. First, IPF uses temporary baseline estimated from the current spectrum to identify peak data points. If the current spectrum contains strong peaks, then the temporary baseline substantially deviates from the true baseline. Some good baseline data points of the spectrum might be mistakenly identified as peak data points and are artificially re-assigned with a low value. Second, if a strong peak is located at the endpoint of the spectrum, then the endpoint region of the estimated baseline might have significant error due to overfitting. This study proposes a search algorithm-based baseline correction method (SA) that aims to compress sample the raw spectrum to a dataset with small number of data points and then convert the peak removal process into solving a search problem in artificial intelligence (AI) to minimize an objective function by deleting peak data points. First, the raw spectrum is smoothened out by the moving average method to reduce noise and then divided into dozens of unequally spaced sections on the basis of Chebyshev nodes. Finally, the minimal points of each section are collected to form a dataset for peak removal through search algorithm. SA selects the mean absolute error (MAE) as the objective function because of its sensitivity to overfitting and rapid calculation. The baseline correction performance of SA is compared with those of three baseline correction methods: Lieber and Mahadevan–Jansen method, adaptive iteratively reweighted penalized least squares method, and improved asymmetric least squares method. Simulated and real FTIR and Raman spectra with polynomial-like baselines are employed in the experiments. Results show that for these spectra, the baseline estimated by SA has fewer error than those by the three other methods.

An Adaptive Invasive Weed Optimization Algorithm

2015 ◽  
Vol 29 (02) ◽  
pp. 1559004 ◽  
Author(s):  
Shuo Peng ◽  
A.-J. Ouyang ◽  
Jeff Jun Zhang
Keyword(s):  
Optimization Algorithm ◽  
Initial Step ◽  
Local Extremum ◽  
Invasive Weed Optimization ◽  
Step Size ◽  
Invasive Weed ◽  
Adaptive Step Size ◽  
Initial Step Size ◽  
Adaptive Step ◽  
Optimization Search

With regards to the low search accuracy of the basic invasive weed optimization algorithm which is easy to get into local extremum, this paper proposes an adaptive invasive weed optimization (AIWO) algorithm. The algorithm sets the initial step size and the final step size as the adaptive step size to guide the global search of the algorithm, and it is applied to 20 famous benchmark functions for a test, the results of which show that the AIWO algorithm owns better global optimization search capacity, faster convergence speed and higher computation accuracy compared with other advanced algorithms.

scholarly journals Cardiometabolic disease and features of depression and bipolar disorder: Population-based, cross-sectional study

2016 ◽  
Vol 208 (4) ◽  
pp. 343-351 ◽  
Author(s):  
Daniel J. Martin ◽  
Zia Ul-Haq ◽  
Barbara I. Nicholl ◽  
Breda Cullen ◽  
Jonathan Evans ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Bipolar Disorder ◽  
Mood Disorder ◽  
Psychotropic Medication ◽  
Large Population ◽  
Population Sample ◽  
Cross Sectional Study ◽  
Cardiometabolic Disease ◽  
Sectional Study ◽  
Cross Sectional

BackgroundThe relative contribution of demographic, lifestyle and medication factors to the association between affective disorders and cardiometabolic diseases is poorly understood.AimsTo assess the relationship between cardiometabolic disease and features of depresion and bipolar disorder within a large population sample.MethodCross-sectional study of 145 991 UK Biobank participants: multivariate analyses of associations between features of depression or bipolar disorder and five cardiometabolic outcomes, adjusting for confounding factors.ResultsThere were significant associations between mood disorder features and ‘any cardiovascular disease’ (depression odds ratio (OR) = 1.15, 95% CI 1.12–1.19; bipolar OR = 1.28, 95% CI 1.14–1.43) and with hypertension (depression OR = 1.15, 95% CI 1.13–1.18; bipolar OR = 1.26, 95% CI 1.12–1.42). Individuals with features of mood disorder taking psychotropic medication were significantly more likely than controls not on psychotropics to report myocardial infarction (depression OR = 1.47, 95% CI 1.24–1.73; bipolar OR = 2.23, 95% CI 1.53–3.57) and stroke (depression OR = 2.46, 95% CI 2.10–2.80; bipolar OR = 2.31, 95% CI 1.39–3.85).ConclusionsAssociations between features of depression or bipolar disorder and cardiovascular disease outcomes were statistically independent of demographic, lifestyle and medication confounders. Psychotropic medication may also be a risk factor for cardiometabolic disease in individuals without a clear history of mood disorder.

scholarly journals Email Vs. Instagram Recruitment Strategies For Online Survey Research

2021 ◽  
Vol 32 (1) ◽  
pp. 67-77
Author(s):  
Rafael R. Moraes ◽  
Marcos B. Correa ◽  
Ândrea Daneris ◽  
Ana B. Queiroz ◽  
João P. Lopes ◽  
...  
Keyword(s):  
Survey Research ◽  
Online Survey ◽  
Large Population ◽  
Population Sample ◽  
Target Population ◽  
Recruitment Strategies ◽  
The Public ◽  
Conversion Rates ◽  
Methodological Aspects ◽  
E Mail

Abstract In this study, we describe a method for reaching a target population (i.e., dentists practicing in Brazil) to engage in survey research using traditional e-mail invites and recruitment campaigns created on Instagram. This study addresses methodological aspects and compares respondents reached by different methods. A pre-tested questionnaire was used and participants were recruited for 10 days via a source list of email addresses and two discrete Instagram organic open campaigns. A total of 3,122 responses were collected: 509 participants were recruited by email (2.1% response rate) and 2,613 by the two Instagram campaigns (20.7% and 11.7% conversion rates), respectively. Response/min collection rates in the first 24 h ranged between 0.23 (email) and 1.09 (first campaign). In total, 98.8% of all responses were received in the first 48 h for the different recruitment strategies. There were significant differences for all demographic variables (p< 0.001) between email and Instagram respondents, except for sex (p=0.37). Instagram respondents were slightly older, had more professional experience (years in practice), and a higher graduate education level than email respondents. Moreover, most email and Instagram respondents worked in the public sector and private practice, respectively. Although both strategies could collect responses from all Brazilian regions, email responses were slightly better distributed across the five territorial areas compared to Instagram. This study provides evidence that survey recruitment of a diverse, large population sample using Instagram is feasible. However, combination of email and Instagram recruitment led to a more diverse population and improved response rates.

scholarly journals Cognitive Abilities in the Wild: Population-scale game-based cognitive assessment

2021 ◽  
Author(s):  
Mads Kock Pedersen ◽  
Carlos Mauricio Castaño Díaz ◽  
Mario Alejandro Alba-Marrugo ◽  
Ali Amidi ◽  
Rajiv Vaid Basaiwmoit ◽  
...  
Keyword(s):  
Cognitive Abilities ◽  
Wild Population ◽  
Full Range ◽  
Large Population ◽  
Population Sample ◽  
The Social ◽  
In The Wild ◽  
Large Population Sample ◽  
Key Questions ◽  
Unique Dataset

Psychology and the social sciences are undergoing a revolution: It has become increasingly clear that traditional lab-based experiments fail to capture the full range of differences in cognitive abilities and behaviours across the general population. Some progress has been made toward devising measures that can be applied at scale across individuals and populations. What has been missing is a broad battery of validated tasks that can be easily deployed, used across different age ranges and social backgrounds, and employed in practical, clinical, and research contexts. Here, we present Skill Lab, a game-based approach allowing the efficient assessment of a suite of cognitive abilities. Skill Lab has been validated outside the lab in a crowdsourced population-size sample recruited in collaboration with the Danish Broadcast Company (Danmarks Radio, DR). Our game-based measures are five times faster to complete than the equivalent traditional measures and replicate previous findings on the decline of cognitive abilities with age in a large population sample. Furthermore, by combining the game data with an in-game survey, we demonstrate that this unique dataset has implication for key questions in social science, challenging the Jack-of-all-Trades theory of entrepreneurship and provide evidence for risk preference being independent of executive functioning.

scholarly journals Thermo-economic analysis and optimization of the steam absorption chiller network plant

2021 ◽  
pp. 58-58
Author(s):  
Farshad Panahizadeh ◽  
Mahdi Hamzehei ◽  
Mahmood Farzaneh-Gord ◽  
Villa Ochoa
Keyword(s):  
Economic Analysis ◽  
Working Condition ◽  
Search Algorithm ◽  
Deep Understanding ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Absorption Chiller ◽  
Absorption Chillers ◽  
Optimization Search

Absorption chillers are one of the most used equipment in industrial, commercial, and domestic applications. For the places where high cooling is required, they are utilized in a network to perform the cooling demand. The main objective of the current study was to find the optimum operating conditions of a network of steam absorption chillers according to energy and economic viewpoints. Firstly, energy and economic analysis and modeling of the absorption chiller network were carried out to have a deep understanding of the network and investigate the effects of operating conditions. Finally, the particle swarm optimization search algorithm was employed to find an optimum levelized total costs of the plant. The absorption chiller network plant of the Marun Petrochemical Complex in Iran was selected as a case study. To verify the simulation results, the outputs of energy modeling were compared with the measured values. The comparison with experimental results indicated that the developed model could predict the working condition of the absorption chiller network with high accuracy. The economic analysis results revealed that the levelized total costs of the plant is 1730 $/kW and the payback period is three years. The optimization findings indicated that working at optimal conditions reduces the levelized total costs of the plant by 8.5%, compared to the design condition.

scholarly journals Visual impairment and blindness in the Xingu Indigenous Park – Brazil

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Arthur Gustavo Fernandes ◽  
Monica Alves ◽  
Roberta Andrade e Nascimento ◽  
Natalia Yumi Valdrighi ◽  
Rafael Cunha de Almeida ◽  
...  
Keyword(s):  
Visual Impairment ◽  
Minority Groups ◽  
Large Population ◽  
Population Sample ◽  
Cross Sectional Study ◽  
Indigenous Populations ◽  
Refractive Errors ◽  
Cross Sectional ◽  
Corrected Visual Acuity ◽  
Large Population Sample

Abstract Background Most estimates of visual impairment and blindness worldwide do not include data from specific minority groups as indigenous populations. We aimed to evaluate frequencies and causes of visual impairment and blindness in a large population sample from the Xingu Indigenous Park. Methods Cross-sectional study performed at Xingu Indigenous Park, Brazil, from 2016 to 2017. Residents from 16 selected villages were invited to participate and underwent a detailed ocular examination, including uncorrected (UVA) and best-corrected visual acuity (BCVA). The main cause of UVA < 20/32 per eye was determined. Results A total of 2,099 individuals were evaluated. Overall, the frequency of visual impairment and blindness was 10.00% (95% CI: 8.72–11.29%) when considering UVA, decreasing to 7.15% (95% CI: 6.04–8.25%) when considering BCVA. For each increasing year on age, the risk  of being in the visually impaired or blind category increased by 9% (p < 0.001). Cataracts (39.1%) and uncorrected refractive errors (29.1%) were the most frequent causes of visual impairment and blindness in this population. The main causes among those aged 45 years and more were cataracts (54.5%) while refractive errors were the main cause in adults aged 18 to 45 years (50.0%) and children up to 18 years old (37.1%). Conclusions A higher frequency of visual impairment and blindness was observed in the indigenous population when compared to worldwide estimates with most of the causes being preventable and/or treatable. Blindness prevention programs should focus on accessibility to eye exam, cataract surgeries and eyeglass distribution.

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