scholarly journals An Adaptive Refined Grid Search Strategy for Assessing Operational Flexibility and Application on Refrigerant Selection

AIChE Journal ◽  
2022 ◽  
Author(s):  
Jiayuan Wang ◽  
Robin Smith ◽  
Lingyu Zhu
Author(s):  
Jiayuan Wang ◽  
Robin Smith ◽  
Lingyu Zhu

A novel adaptive refined grid search strategy is developed for representative characterization of process feasible region boundaries and accurate estimation of its hypervolume. In particular, a linked list data structure adopted from the field of computer science is used to maintain the grid connectivity information. A uniform perturbation scheme is used to refine the search only near boundaries. The volumetric flexibility index FI_V is calculated directly from a summation of feasible hypercubes in the grid, without the need to apply shape reconstruction techniques. The proposed adaptive grid search strategy can capture complex region shapes with reduced sampling costs and without randomness for better reproducibility. Operational flexibility is optimized traditionally at a process scale. A case study on refrigerant selection is presented to demonstrated that the developed strategy could be combined within a computer-aided molecular design framework for operational flexibility optimization in molecular scale.


Author(s):  
Dorian Ruiz Alonso ◽  
Claudia Zepeda Cortés ◽  
Hilda Castillo Zacatelco ◽  
José Luis Carballido Carranza

In this work, we propose the extension of a methodology for the multi-label classification of feedback according to the Hattie and Timperley feedback model, incorporating a hyperparameter tuning stage. It is analyzed whether the incorporation of the hyperparameter tuning stage prior to the execution of the algorithms support vector machines, random forest and multi-label k-nearest neighbors, improves the performance metrics of multi-label classifiers that automatically locate the feedback generated by a teacher to the activities sent by students in online courses on the Blackboard platform at the task, process, regulation, praise and other levels proposed in the feedback model by Hattie and Timperley. The grid search strategy is used to refine the hyperparameters of each algorithm. The results show that the adjustment of the hyperparameters improves the performance metrics for the data set used.


2012 ◽  
Vol 82 (4) ◽  
pp. 237-259 ◽  
Author(s):  
Moshe Ben-Shoshan

This review summarizes studies discussing vitamin D status in adults and reveals that vitamin D deficiency/insufficiency is highly prevalent in adults and that current fortification and supplementation policies are inadequate. Background and aims: Studies suggest a crucial role for adequate vitamin D status in various health conditions including bone metabolism, cancer, cardiovascular diseases, and allergies. However, relatively little is known about poor vitamin D status and unmet needs in adults. This report aims to highlight the contribution of epidemiologic studies (through the identification of health effects and societal burden) to the development of vitamin D fortification and supplementation policies and reveal unmet global challenges in adults. Methods: In order to assess worldwide vitamin D status in adults, the search strategy combined the medical literature database MEDLINE (using PubMed) for the time period between January 1, 1980 and February 28, 2011, using the key words “vitamin D” “deficiency” and “insufficiency”, and included articles in which access to full text was possible and in which healthy adults were assessed according to one of four commonly used vitamin D threshold classifications. Results: This report reveals that vitamin D deficiency occurs in 4.10 % [95 % CI (confidence interval), 3.93 %, 4.27 %] to 55.05 % (54.07 %, 56.03 %) of adults, while insufficiency occurs in 26.07 % (24.82 %, 27.33 %) to 78.50 % (77.85 %, 79.16 %), depending on the classification used. However, lack of overlap in CIs and high value of I2 statistics indicate considerable heterogeneity between studies. Further, certain populations (i. e. dark-skinned individuals, immigrants, and pregnant women) may be at higher risk for poor vitamin D status. Conclusion: Current policies for vitamin D supplementation and fortification are inadequate and new guidelines are required to improve vitamin D status in adults.


2013 ◽  
Vol 32 (12) ◽  
pp. 3326-3330
Author(s):  
Yin-xue ZHANG ◽  
Xue-min TIAN ◽  
Yu-ping CAO

2012 ◽  
Author(s):  
Benoit Chevalier-Roignant ◽  
Christoph M. Flath ◽  
Lenos Trigeorgis

2020 ◽  
Vol 17 (5) ◽  
pp. 472-486
Author(s):  
Lucy Beishon ◽  
Kannakorn Intharakham ◽  
David Swienton ◽  
Ronney B. Panerai ◽  
Thompson G. Robinson ◽  
...  

Background: Cognitive Training (CT) has demonstrated some benefits to cognitive and psychosocial function in Mild Cognitive Impairment (MCI) and early dementia, but the certainty related to those findings remains unclear. Therefore, understanding the mechanisms by which CT improves cognitive functioning may help to understand the relationships between CT and cognitive function. The purpose of this review was to identify the evidence for neuroimaging outcomes in studies of CT in MCI and early Alzheimer’s Disease (AD). Methods: Medline, Embase, Web of Science, PsycINFO, CINAHL, and The Cochrane Library were searched with a predefined search strategy, which yielded 1778 articles. Studies were suitable for inclusion where a CT program was used in patients with MCI or AD, with a structural or functional Magnetic Resonance Imaging (MRI) outcome. Studies were assessed for quality using the Downs and Black criteria. Results: Medline, Embase, Web of Science, PsycINFO, CINAHL, and The Cochrane Library were searched with a predefined search strategy, which yielded 1778 articles. Studies were suitable for inclusion where a CT program was used in patients with MCI or AD, with a structural or functional Magnetic Resonance Imaging (MRI) outcome. Studies were assessed for quality using the Downs and Black criteria. Conclusions: CT resulted in variable functional and structural changes in dementia, and conclusions are limited by heterogeneity and study quality. Larger, more robust studies are required to correlate these findings with clinical benefits from CT.


2020 ◽  
Author(s):  
Cheng Hang Wu ◽  
Ching Ju Chiu ◽  
Yen Ju Liou ◽  
Chun Ying Lee ◽  
Susan C. Hu

BACKGROUND There is still no consensus on research terms for smart healthcare worldwide. The study conducted by Lewis 10 years ago showed extending geographic access was the major health purpose of health-related information communication technology (ICT), but today's situation may be different because of the rapid development of smart healthcare. Objective: The main aim of this study is to classify recent smart healthcare interventions. Therefore, this scoping review was conducted as a feasible tool for exploring this domain and summarizing related research findings. OBJECTIVE The main aim of this study is to classify recent smart healthcare interventions. Therefore, this scoping review was conducted as a feasible tool for exploring this domain and summarizing related research findings. METHODS The scoping review relies on the analysis of previous reviews of smart healthcare interventions assessed for their effectiveness in the framework of a systematic review and/or meta-analysis. The search strategy was based on the identification of smart healthcare interventions reported as the proposed keywords. In the analysis, the reviews published from January 2015 to December 2019 were included. RESULTS The number of publications for smart healthcare's systematic reviews has continued to grow in the past five years. The search strategy yielded 210 systematic reviews and/or meta-analyses addressed to target groups of interest. 68.5% of these publications used mobile health as a keyword. According to the classification by Lewis, 37.62% of the literature was applied to extend geographic access. According to the classification by the Joint Commission of Taiwan (JCT), 48.84% of smart healthcare was applied in clinical areas, and 60% of it was applied in outpatient medical services. CONCLUSIONS Smart healthcare interventions are being widely used in clinical settings and for disease management. The research of mobile health has received the most attention among smart healthcare interventions. The main purpose of mobile health was used to extend geographic access to increase medical accessibility in clinical areas. CLINICALTRIAL none


Algorithms ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 139 ◽  
Author(s):  
Vincenzo Cutello ◽  
Georgia Fargetta ◽  
Mario Pavone ◽  
Rocco A. Scollo

Community detection is one of the most challenging and interesting problems in many research areas. Being able to detect highly linked communities in a network can lead to many benefits, such as understanding relationships between entities or interactions between biological genes, for instance. Two different immunological algorithms have been designed for this problem, called Opt-IA and Hybrid-IA, respectively. The main difference between the two algorithms is the search strategy and related immunological operators developed: the first carries out a random search together with purely stochastic operators; the last one is instead based on a deterministic Local Search that tries to refine and improve the current solutions discovered. The robustness of Opt-IA and Hybrid-IA has been assessed on several real social networks. These same networks have also been considered for comparing both algorithms with other seven different metaheuristics and the well-known greedy optimization Louvain algorithm. The experimental analysis conducted proves that Opt-IA and Hybrid-IA are reliable optimization methods for community detection, outperforming all compared algorithms.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Pattarapol Sumreddee ◽  
El Hamidi Hay ◽  
Sajjad Toghiani ◽  
Andrew Roberts ◽  
Samuel E. Aggrey ◽  
...  

Abstract Background Although inbreeding caused by the mating of animals related through a recent common ancestor is expected to have more harmful effects on phenotypes than ancient inbreeding (old inbreeding), estimating these effects requires a clear definition of recent (new) and ancient (old) inbreeding. Several methods have been proposed to classify inbreeding using pedigree and genomic data. Unfortunately, these methods are largely based on heuristic criteria such as the number of generations from a common ancestor or length of runs of homozygosity (ROH) segments. To mitigate these deficiencies, this study aimed to develop a method to classify pedigree and genomic inbreeding into recent and ancient classes based on a grid search algorithm driven by the assumption that new inbreeding tends to have a more pronounced detrimental effect on traits. The proposed method was tested using a cattle population characterized by a deep pedigree. Results Effects of recent and ancient inbreeding were assessed on four growth traits (birth, weaning and yearling weights and average daily gain). Thresholds to classify inbreeding into recent and ancient classes were trait-specific and varied across traits and sources of information. Using pedigree information, inbreeding generated in the last 10 to 11 generations was considered as recent. When genomic information (ROH) was used, thresholds ranged between four to seven generations, indicating, in part, the ability of ROH segments to characterize the harmful effects of inbreeding in shorter periods of time. Nevertheless, using the proposed classification method, the discrimination between new and old inbreeding was less robust when ROH segments were used compared to pedigree. Using several model comparison criteria, the proposed approach was generally better than existing methods. Recent inbreeding appeared to be more harmful across the growth traits analyzed. However, both new and old inbreeding were found to be associated with decreased yearling weight and average daily gain. Conclusions The proposed method provided a more objective quantitative approach for the classification of inbreeding. The proposed method detected a clear divergence in the effects of old and recent inbreeding using pedigree data and it was superior to existing methods for all analyzed traits. Using ROH data, the discrimination between old and recent inbreeding was less clear and the proposed method was superior to existing approaches for two out of the four analyzed traits. Deleterious effects of recent inbreeding were detected sooner (fewer generations) using genomic information than pedigree. Difference in the results using genomic and pedigree information could be due to the dissimilarity in the number of generations to a common ancestor. Additionally, the uncertainty associated with the identification of ROH segments and associated inbreeding could have an effect on the results. Potential biases in the estimation of inbreeding effects may occur when new and old inbreeding are discriminated based on arbitrary thresholds. To minimize the impact of inbreeding, mating designs should take the different inbreeding origins into consideration.


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