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Stratified subsampling for regression analysis of big count response data

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AIP Conference Proceedings 2023年第1期2756卷

作者： Yeh-Ching Low Seng-Huat Ong Department of Computing and Information Systems School of Engineering and Technology Sunway University 47500 Selangor Malaysia Institute of Actuarial Science and Data Analytics UCSI University 56000 Kuala Lumpur Malaysia

Count frequency data are found in many applications such as traffic accident analysis, car insurance claims, hospital admissions records and adverse vaccine reaction data. In some cases, these data have high zero counts and/or heavy tails due to cases such as no claim or no incidence in insurance and accident data, respectively. In regression modelling, the data size can be formidable due to either large sample size and/or large number of covariates or predictors which leads to computational challenges. Although many computer engineering solutions are available through supercomputers and parallel computing, there exists limitations due to cost and accessibility. As such, statistical solutions have been considered to ameliorate the challenges posed by regression modelling of big data. In general, these statistical solutions are classified as divide and conquer approach, fine-to-coarse method and subsampling methods. To address the problem of large data size in count regression modelling, we propose a stratified subsampling strategy according to frequency classes with shrinkage leveraging for statistical inference. An attractive feature of this strategy is in its ability to preserve the characteristics of data like over dispersion, high zero counts and/or heavy-tailed. A Monte Carlo simulation study is conducted to investigate the performance of the proposed stratified subsampling method in regression modelling with big count data. The regression analysis will be illustrated using a family of mixed Poisson regression models which have been shown to be flexible in its ability to model count data with high zero counts and/or a long tail.

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Big data: Prospects and Challenges

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Vikalpa 2015年第1期40卷 74 - 96页

作者： Janakiraman Moorthy Rangin Lahiri Neelanjan Biswas Dipyaman Sanyal Jayanthi Ranjan Krishnadas Nanath Pulak Ghosh (Coordinator) Director and Professor of Marketing at the Institute of Management Technology Dubai. Earlier he was Professor of Marketing at the IIM Calcutta and IIM Lucknow. He received his PhD from IIM Ahmedabad. His recent research papers were published in the leading scholarly ournals such as Marketing Science British Food Journal Journal of Information Technology Case and Application Research Journal of Database Marketing & Customer Strategy Management. He has wide experience in the banking and investment industry. He was earlier the Global Research and Project Director of the Institute for Customer Relationship Management Atlanta USA. He was the Convener of the prestigious CAT Exam 2011. e-mail: Practice Director leading Atos India's CRM practice while supporting Strategic Business Development for North American Market. With an experience of more than 15 years Rangin has worked extensively as a Business Consultant in Information Technology (Sales Automation Marketing & Service Management area) Customer Data Management and CRM Analytics. e-mail: Business Consultant at Atos with extensive experience in Business Analysis Risk Management Analytics Business Development Presales Solution Ideation on Enterprise Data Management Enterprise Reference Data and Master Data Management area. e-mail: founder and CEO of dono consulting a boutique quantitative analytics and investment research firm. He has worked for leading financial firms in New York and India including Dow Jones Blackstone Sorin Capital (VP Quantitative Modeling) and Thomson Reuters (Head of Real Estate Analytics). A CFA charter holder and Commonwealth Scholar Deep has an MS (Applied Economics) from University of Texas Dallas and an MA (Economics) from Jadavpur University e-mail: Professor in the Information Systems Group of the Institute of Management Technology Ghaziabad. Her PhD is in the field of data mining from Jamia Millia Islamia Central University India. She has published five edited books. She is serving on the editorial b

Ti interstitial flows giving rutile TiO2 reoxidation process enhanced in (001) surface

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arXiv 2019年

作者： Ichibha, Tom Benali, Anouar Hongo, Kenta Maezono, Ryo School of Information Science JAIST 1-1 Asahidai NomiIshikawa923-1292 Japan Computational Science Division Argonne National Laboratory 9700 Cass Avenue LemontIL60439 United States Research Center for Advanced Computing Infrastructure JAIST 1-1 Asahidai NomiIshikawa923-1292 Japan Center for Materials Research by Information Integration Research and Services Division of Materials Data and Integrated System National Institute for Materials Science 1-2-1 Sengen Tsukuba305-0047 Japan PRESTO Japan Science and Technology Agency 4-1-8 Honcho Kawaguchi-shi Saitama322-0012 Japan Computational Engineering Applications Unit RIKEN 2-1 Hirosawa Wako Saitama351-0198 Japan

We revisited ab initio evaluations of the energy barriers along the possible diffusion paths of the defects in rutile TiO2. By using a method carefully considering the cancellation of the self-interaction, Ti interstitials hopping along c-axis are identified as the major diffusion directing to [001] surface. The conclusion is contradicting to any of previous theoretical works, and the discrepancy is explained by the overestimation of the radius of defects due to the poor cancellations in the previous works. The updated prediction here can explain the superior photocatalysis activity in [001] surface to [110]. Copyright © 2019, The Authors. All rights reserved.

关键词： Titanium dioxide

Ab initio evaluation of complexation energies for cyclodextrin drug inclusion complexes

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arXiv 2020年

作者： Oqmhula, Kenji Hongo, Kenta Maezono, Ryo Ichibha, Tom School of Materials Science JAIST 1-1 Asahidai NomiIshikawa923-1292 Japan Research Center for Advanced Computing Infrastructure JAIST 1-1 Asahidai NomiIshikawa923-1292 Japan Center for Materials Research by Information Integration Research and Services Division of Materials Data and Integrated System National Institute for Materials Science 1-2-1 Sengen Tsukuba305-0047 Japan PRESTO Japan Science and Technology Agency 4-1-8 Honcho Kawaguchi-shi Saitama322-0012 Japan Computational Engineering Applications Unit RIKEN 2-1 Hirosawa Wako Saitama351-0198 Japan School of Information Science JAIST 1-1 Asahidai NomiIshikawa923-1292 Japan

We examined the reliability of exchange-correlation functionals for molecular encapsulations combined by van der Waals forces, comparing their predictions with those of diffusion Monte Carlo method. We established that functionals with D3 dispersion force correction and including sufficient proportion of exact-exchange in long-ranged interaction can comparatively reliably estimate the binding strength. Our finding agrees with a previous ab initio study on argon dimer. However we found that even such functionals may not be able to distinguish the energy differences among different conformations. Copyright © 2020, The Authors. All rights reserved.

关键词： Van der Waals forces

Minimizing cost and backorder risk through customer priority on spares inventory

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Journal of Physics: Conference Series 2019年第1期1218卷

作者： V Lukitosari A P Subriadi I Siyamah Mathematics Department Faculty of Mathematics Computing and Data Science Sepuluh Nopember Institute of Technology (ITS) Surabaya 60111 Indonesia Department of Information System Sepuluh Nopember Institute of Technology (ITS) Surabaya 60111 Indonesia

Spare parts demands usually occur due to the need to replace spare parts on damaged equipment. Uncertain demands and many types of spare parts require complex management. Therefore, the management of spare parts is very challenging. In this study, we developed a spare part inventory method by considering priorities based on customer class. Customers will be grouped according to the number of demands. The number of requests becomes a fill rate priority. Any request that cannot be fulfilled will have backorder risk. This customer prioritization aims to minimize costs and backorder risks. The difference in customer class aims to minimize total inventory costs. Spare parts will be issued based on the queue discipline which is first in first out. The inventory model is solved by the Lagrange multiplier method. Model verification is carried out in real practice in illustrative examples. The results of the research show that customer priorities that are carried out in the provision of the fulfilment of spare parts can reduce costs and backorder risks.

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Numerical simulation of endovascular treatment options for cerebral aneurysms

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arXiv 2024年

作者： Frank, Martin Holzberger, Fabian Horvat, Medeea Kirschke, Jan Mayr, Matthias Muhr, Markus Nebulishvili, Natalia Popp, Alexander Schwarting, Julian Wohlmuth, Barbara University of the Bundeswehr Munich Institute for Mathematics and Computer-Based Simulation Werner-Heisenberg-Weg 39 Neubiberg85577 Germany Technical University of Munich School of Computation Information and Technology Department of Mathematics Chair for Numerical Mathematics Boltzmannstr. 3 Garching85748 Germany Technical University of Munich Department of Neuroradiology Ismaninger Str. 22 Munich81675 Germany University of the Bundeswehr Munich Data Science & Computing Lab Werner-Heisenberg-Weg 39 Neubiberg85577 Germany

Predicting the long-term success of endovascular interventions in the clinical management of cerebral aneurysms requires detailed insight into the patient-specific physiological conditions. In this work, we not only propose numerical representations of endovascular medical devices such as coils, flow diverters or Woven EndoBridge but also outline numerical models for the prediction of blood flow patterns in the aneurysm cavity right after a surgical intervention. Detailed knowledge about the post-surgical state then lays the basis to assess the chances of a stable occlusion of the aneurysm required for a long-term treatment success. To this end, we propose mathematical and mechanical models of endovascular medical devices made out of thin metal wires. These can then be used for fully resolved flow simulations of the post-surgical blood flow, which in this work will be performed by means of a Lattice Boltzmann method applied to the incompressible Navier-Stokes equations and patient-specific geometries. To probe the suitability of homogenized models, we also investigate poro-elastic models to represent such medical devices. In particular, we examine the validity of this modeling approach for flow diverter placement across the opening of the aneurysm cavity. For both approaches, physiologically meaningful boundary conditions are provided from reduced-order models of the vascular system. The present study demonstrates our capabilities to predict the post-surgical state and lays a solid foundation to tackle the prediction of thrombus formation and, thus, the aneurysm occlusion in a next step. © 2024, CC BY-NC-ND.

关键词： Navier Stokes equations

Inventory models for short life cycle clothing products use a logistic growth model

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Journal of Physics: Conference Series 2020年第1期1490卷

作者： V Lukitosari A P Subriadi Mathematics Department Faculty of Mathematics Computing and Data Science Sepuluh Nopember Institute of Technology (ITS) Surabaya 60111 Indonesia Department of Information System Sepuluh Nopember Institute of Technology (ITS) Surabaya 60111 Indonesia

Clothes are products that follow short-life fashion and market demand. Products with a short lifetime occur due to technological developments and/or changes in market tastes. The clothing industry is one of the industries that has a short and obsolete sales period in stages. The excess number of products that accumulate in the warehouse due to obsolescence can cause the company to get a profit that is not optimal. One strategy to increase demand for the product is to apply discounts. There are two types of discounts used, namely a single discount and multiple discounts. The demand function of inventory model is considered analogous to the logistic growth model. The results show profit is maximized to get optimal order quantity and optimal discount price.

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Efficient Low-Resolution Face Recognition via Bridge Distillation

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arXiv 2024年

作者： Ge, Shiming Zhao, Shengwei Li, Chenyu Zhang, Yu Li, Jia The Institute of Information Engineering Chinese Academy of Sciences Beijing100095 China School of Cyber Security University of Chinese Academy of Sciences Beijing100049 China SenseTime Group Limited 100084 China The State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and Engineering Beihang University China The Beijing Advanced Innovation Center for Big Data and Brain Computing Beihang University Beijing100191 China The Peng Cheng Laboratory Shenzhen518055 China

Face recognition in the wild is now advancing towards light-weight models, fast inference speed and resolution-adapted capability. In this paper, we propose a bridge distillation approach to turn a complex face model pretrained on private high-resolution faces into a light-weight one for low-resolution face recognition. In our approach, such a cross-dataset resolution-adapted knowledge transfer problem is solved via two-step distillation. In the first step, we conduct cross-dataset distillation to transfer the prior knowledge from private high-resolution faces to public high-resolution faces and generate compact and discriminative features. In the second step, the resolution-adapted distillation is conducted to further transfer the prior knowledge to synthetic low-resolution faces via multi-task learning. By learning low-resolution face representations and mimicking the adapted high-resolution knowledge, a light-weight student model can be constructed with high efficiency and promising accuracy in recognizing low-resolution faces. Experimental results show that the student model performs impressively in recognizing low-resolution faces with only 0.21M parameters and 0.057MB memory. Meanwhile, its speed reaches up to 14,705, 934 and 763 faces per second on GPU, CPU and mobile phone, respectively. Copyright © 2024, The Authors. All rights reserved.

关键词： Multi-task learning

Digital Over-the-Air Federated Learning in Multi-Antenna Systems

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arXiv 2023年

作者： Wang, Sihua Chen, Mingzhe Shen, Cong Yin, Changchuan Brinton, Christopher G. The Beijing Laboratory of Advanced Information Network The Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing100876 China The Department of Electrical and Computer Engineering Institute for Data Science and Computing University of Miami Coral GablesFL33146 United States The Charles L. Brown Department of Electrical and Computer Engineering University of Virginia CharlottesvilleVA United States The School of Electrical and Computer Engineering Purdue University West LafayetteIN United States

In this paper, the performance optimization of federated learning (FL), when deployed over a realistic wireless multiple-input multiple-output (MIMO) communication system with digital modulation and over-the-air computation (AirComp) is studied. In particular, a MIMO system is considered in which edge devices transmit their local FL models (trained using their locally collected data) to a parameter server (PS) using beamforming to maximize the number of devices scheduled for transmission. The PS, acting as a central controller, generates a global FL model using the received local FL models and broadcasts it back to all devices. Due to the limited bandwidth in a wireless network, AirComp is adopted to enable efficient wireless data aggregation. However, fading of wireless channels can produce aggregate distortions in an AirComp-based FL scheme. To tackle this challenge, we propose a modified federated averaging (FedAvg) algorithm that combines digital modulation with AirComp to mitigate wireless fading while ensuring the communication efficiency. This is achieved by a joint transmit and receive beamforming design, which is formulated as an optimization problem to dynamically adjust the beamforming matrices based on current FL model parameters so as to minimize the transmitting error and ensure the FL performance. To achieve this goal, we first analytically characterize how the beamforming matrices affect the performance of the FedAvg in different iterations. Based on this relationship, an artificial neural network (ANN) is used to estimate the local FL models of all devices and adjust the beamforming matrices at the PS for future model transmission. The algorithmic advantages and improved performance of the proposed methodologies are demonstrated through extensive numerical experiments. Copyright © 2023, The Authors. All rights reserved.

关键词： Beamforming