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2022 ◽  
Author(s):  
Sachin Patade ◽  
Vaughan Phillips ◽  
Deepak Waman ◽  
Akash Deshmukh ◽  
Ashok Kumar Gupta ◽  
...  

Abstract. A new empirical parameterization (EP) for multiple groups of primary biological aerosol particles (PBAPs) is implemented in the aerosol cloud model (AC) to investigate their roles as ice-nucleating particles (INPs). The EP describes the heterogeneous ice nucleation by (1) fungal spores, (2) bacteria, (3) pollen, (4) detritus of plants, animals, and viruses, and (5) algae. Each group includes fragments from the originally emitted particles. A high-resolution simulation of a midlatitude mesoscale squall line by AC is validated against airborne and ground observations. Sensitivity tests are carried out by varying the initial vertical profiles of the loadings of individual PBAP groups. The resulting changes in warm and ice microphysical parameters are investigated. Overall, PBAPs have little effect on the ice phase, especially in the convective region. In the stratiform region, increasing the initial PBAP loadings by a factor of 100 resulted in less than 60 % change in ice number concentrations. The total ice concentration is mostly controlled by various mechanisms of secondary ice production (SIP). However, when SIP is artificially prohibited in sensitivity tests, increasing the PBAP loading by a factor of 100 has no significant effect on the ice phase. Further sensitivity tests revealed that PBAPs have little effect on surface precipitation as well as on shortwave and longwave flux.


2022 ◽  
Vol 10 (1) ◽  
Author(s):  
Giacomo Solano ◽  
Veronique Schutjens ◽  
Jan Rath

AbstractThis article addresses transnational migrant entrepreneurship, which refers to migrants involved in cross-border entrepreneurial activities. Previous models and concepts in migrant entrepreneurship studies have not fully succeeded in recognising the role played by differential groups and places in the pursuit of opportunities by transnational migrant entrepreneurs. This is due to a tendency to focus on the country of residence as well as on the inclination to view migrant entrepreneurs as members of a coherent ethnic or national group. To help fill this gap, we propose a new model combining the concept of multifocality, covering the simultaneous involvement of migrant entrepreneurs in both multiple places and multiple groups, with group modes of behaviour as an additional dimension influencing the opportunity structure. The case of Moroccan transnational entrepreneurs in Amsterdam shows that the role of multifocality in place, in combination with group modes of behaviour, is critical when it comes to pursuing entrepreneurial opportunities.


2022 ◽  
Vol 413 ◽  
pp. 126624
Author(s):  
Xianjia Wang ◽  
Rui Ding ◽  
Jinhua Zhao ◽  
Cuiling Gu
Keyword(s):  

Mathematics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 39
Author(s):  
Qihang Huang ◽  
Yulin He ◽  
Zhexue Huang

To provide more external knowledge for training self-supervised learning (SSL) algorithms, this paper proposes a maximum mean discrepancy-based SSL (MMD-SSL) algorithm, which trains a well-performing classifier by iteratively refining the classifier using highly confident unlabeled samples. The MMD-SSL algorithm performs three main steps. First, a multilayer perceptron (MLP) is trained based on the labeled samples and is then used to assign labels to unlabeled samples. Second, the unlabeled samples are divided into multiple groups with the k-means clustering algorithm. Third, the maximum mean discrepancy (MMD) criterion is used to measure the distribution consistency between k-means-clustered samples and MLP-classified samples. The samples having a consistent distribution are labeled as highly confident samples and used to retrain the MLP. The MMD-SSL algorithm performs an iterative training until all unlabeled samples are consistently labeled. We conducted extensive experiments on 29 benchmark data sets to validate the rationality and effectiveness of the MMD-SSL algorithm. Experimental results show that the generalization capability of the MLP algorithm can gradually improve with the increase of labeled samples and the statistical analysis demonstrates that the MMD-SSL algorithm can provide better testing accuracy and kappa values than 10 other self-training and co-training SSL algorithms.


2021 ◽  
pp. 096228022110619
Author(s):  
Yuanke Qu ◽  
Chun Yin Lee ◽  
KF Lam

Infectious diseases, such as the ongoing COVID-19 pandemic, pose a significant threat to public health globally. Fatality rate serves as a key indicator for the effectiveness of potential treatments or interventions. With limited time and understanding of novel emerging epidemics, comparisons of the fatality rates in real-time among different groups, say, divided by treatment, age, or area, have an important role to play in informing public health strategies. We propose a statistical test for the null hypothesis of equal real-time fatality rates across multiple groups during an ongoing epidemic. An elegant property of the proposed test statistic is that it converges to a Brownian motion under the null hypothesis, which allows one to develop a sequential testing approach for rejecting the null hypothesis at the earliest possible time when statistical evidence accumulates. This property is particularly important as scientists and clinicians are competing with time to identify possible treatments or effective interventions to combat the emerging epidemic. The method is widely applicable as it only requires the cumulative number of confirmed cases, deaths, and recoveries. A large-scale simulation study shows that the finite-sample performance of the proposed test is highly satisfactory. The proposed test is applied to compare the difference in disease severity among Wuhan, Hubei province (exclude Wuhan) and mainland China (exclude Hubei) from February to March 2020. The result suggests that the disease severity is potentially associated with the health care resource availability during the early phase of the COVID-19 pandemic in mainland China.


Twejer ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 7-64
Author(s):  
Qais Kakl Tawfiq ◽  
◽  
Chia Ali Mustafa ◽  
Keyword(s):  

تویژینه‌وه‌كه‌ له ‌ئاستی تیۆریدا، هه‌وڵێكه‌ بۆ ناساندنی ستراتیژیه‌تی گوتار له‌ ئاسته‌كانی (به‌رهه‌مهێنان و شیكردنه‌وه‌ی) گوتار، په‌یوه‌ست به‌ (ستراتیژیه‌تی زمان و كۆزانیاریی زمانی). پاشان به‌ دیارخستی ڕۆڵ و ئه‌ركی كه‌ره‌سته‌ زمانییه‌كان‌‌ له‌ داڕشتنی ستراتیژیه‌تی گوتاردا. له‌گه‌ڵ ناساندن و ڕۆڵی (به‌ڵگه‌ی زمانی و بورهانی زمانی) له‌ پڕۆسه‌ی ڕازیكردنی وه‌رگردا. بۆ ئه‌م مه‌به‌سته‌ ئایدۆلۆجیای (نه‌ته‌وه‌یی و ئاینی) له‌ گوتاری سیاسی كوردی له‌ پڕۆسه‌ی هه‌ڵبژاردندا به‌ بنه‌ما وه‌رگیراوه‌. توێژینه‌وه‌كه‌، ‌بێجگه‌ له‌ پێشه‌كی ئه‌نجام، له‌ دوو به‌ش پێكدێت. به‌شی یه‌كه‌م: به‌شی تیۆریی توێژینه‌وه‌كه‌یه‌، سه‌ره‌تا ناساندنی گوتاره‌ له‌ ئاستی زماندا، دواتر ناساندنی تیۆری ستراتیژیه‌تی گوتار و دیاریكردنی ڕه‌گه‌زه‌كانی ستراتیژیه‌تی گوتاره‌، پاشان په‌یوه‌ندی ستراتیژیه‌تی گوتار به‌ ئاسته‌كانی زمان خراوه‌ته‌ڕوو. له‌ دواییدا باس له‌ به‌ڵگه‌ی گوتار و شێوازی به‌ڵگه‌ له‌ گوتاردا كراوه‌. به‌شی دووه‌م: به‌شی كاره‌كیی توێژینه‌وه‌كه‌یه‌، گوتاری قه‌واره‌ سیاسییه‌كان شیكاركراون و جۆری ستراتیژیه‌تی به‌كارهاتوو و به‌ڵگه‌ی زمانی په‌یوه‌ست به‌ جۆری ستراتیژیییەكه‌ له‌ خشته‌یه‌كدا دیاریكراوه‌. دوای خستنه‌ڕوو و گفتوگۆی داتاكان، ئه‌نجام و لیستی سه‌رچاوه‌كان و پوخته‌ی توێژینه‌وه‌كه‌ به‌ هه‌ردوو زمانی عه‌ره‌بی و ئینگلیزی نووسراوه‌، له‌ كۆتاییشدا نموونه‌ی گوتاری قه‌واره ‌سیاسییه‌كان دانراوه‌.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 67-67
Author(s):  
Laura Baker

Abstract The spotlight on interventions to protect brain health and prevent Alzheimer’s disease (AD) has recently widened to include risk modification. In the last 20 years, evidence continues to build to support cognition-enhancing effects of individual lifestyle components, which include, among others, physical exercise, diet, cognitive training, and cardiovascular risk management. A recent evolution of lifestyle trials is to combine these components as part of intervention delivery. The potential benefit of this approach on cognition in older adults, first showcased in the FINGER trial, is now under investigation by multiple groups across the nation and the globe. The multidomain approach offers important opportunities to boost lifestyle intervention ‘dose’, to examine inter-component synergistic effects, and for intervention tailoring to meet specific needs and limitations. Harmonization and data-sharing will be essential to meaningfully address the question of whether multidomain lifestyle modification can indeed be ‘medicine’ to protect brain health and reduce AD risk.


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