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arXiv 2021年

作者： Izawa, Syun Kitai, Koki Tanaka, Shu Tamura, Ryo Tsuda, Koji Department of Computational Biology and Medical Sciences Graduate School of Frontier Sciences University of Tokyo Kashiwa277-8561 Japan Department of Mechanical Engineering University of Tokyo Tokyo113-8654 Japan Department of Applied Physics and Physico-Informatics Keio University Yokohama223-8522 Japan Green Computing System Research Organization Waseda University Tokyo162-0042 Japan International Center for Materials Nanoarchitectonics National Institute for Materials Science Tsukuba305-0047 Japan Research and Services Division of Materials Data and Integrated System National Institute for Materials Science Tsukuba305-0047 Japan RIKEN Center for Advanced Intelligence Project Tokyo103-0027 Japan

A black-box optimization algorithm such as Bayesian optimization finds extremum of an unknown function by alternating inference of the underlying function and optimization of an acquisition function. In a high-dimensional space, such algorithms perform poorly due to the difficulty of acquisition function optimization. Herein, we apply quantum annealing (QA) to overcome the difficulty in the continuous black-box optimization. As QA specializes in optimization of binary problems, a continuous vector has to be encoded to binary, and the solution of QA has to be translated back. Our method has the following three parts: 1) Random subspace coding based on axis-parallel hyperrectangles from continuous vector to binary vector. 2) A quadratic unconstrained binary optimization (QUBO) defined by acquisition function based on nonnegative-weighted linear regression model which is solved by QA. 3) A penalization scheme to ensure that the QA solution can be translated back. It is shown in benchmark tests that its performance using D-Wave AdvantageTM quantum annealer is competitive with a state-of-the-art method based on the Gaussian process in high-dimensional problems. Our method may open up a new possibility of quantum annealing and other QUBO solvers including quantum approximate optimization algorithm (QAOA) using a gated-quantum computers, and expand its range of application to continuous-valued problems. © 2021, CC BY.

关键词： Annealing

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Getting the most out of maths: How to coordinate mathematical modelling research to support a pandemic, lessons learnt from three initiatives that were part of the COVID-19 response in the UK

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Journal of Theoretical Biology 2023年 557卷 111332页

作者： Dangerfield, Ciara E. David Abrahams, I. Budd, Chris Butchers, Matt Cates, Michael E. Champneys, Alan R. Currie, Christine S.M. Enright, Jessica Gog, Julia R. Goriely, Alain Déirdre Hollingsworth, T. Hoyle, Rebecca B. INI Professional Services Isham, Valerie Jordan, Joanna Kaouri, Maha H. Kavoussanakis, Kostas Leeks, Jane Maini, Philip K. Marr, Christie Merritt, Clare Mollison, Denis Ray, Surajit Thompson, Robin N. Wakefield, Alexandra Wasley, Dawn Isaac Newton Institute to Mathematical Sciences University of Cambridge United Kingdom Joint UNIversities Pandemic and Epidemiological Research (JUNIPER) Consortium United Kingdom Department for Applied Mathematics and Theoretical Physics University of Cambridge United Kingdom Department of Mathematics University of Bath United Kingdom Department of Engineering Mathematics University of Bristol United Kingdom School of Mathematical Sciences University of Southampton United Kingdom School of Computing Science University of Glasgow United Kingdom Mathematical Institute University of Oxford United Kingdom Big Data Institute Li Ka Shing Centre for Health Information and Discovery University of Oxford United Kingdom Department of Statistical Science University College London United Kingdom Independent United Kingdom EPCC The University of Edinburgh United Kingdom Department of Actuarial Mathematics and Statistics Heriot-Watt University United Kingdom School of Mathematics and Statistics University of Glasgow United Kingdom Mathematics Institute University of Warwick United Kingdom Zeeman Institute for Systems Biology and Infectious Disease Epidemiology Research University of Warwick United Kingdom The Royal Society London United Kingdom International Centre for Mathematical Sciences University of Edinburgh & Heriot-Watt University United Kingdom

In March 2020 mathematics became a key part of the scientific advice to the UK government on the pandemic response to COVID-19. Mathematical and statistical modelling provided critical information on the spread of the virus and the potential impact of different interventions. The unprecedented scale of the challenge led the epidemiological modelling community in the UK to be pushed to its limits. At the same time, mathematical modellers across the country were keen to use their knowledge and skills to support the COVID-19 modelling effort. However, this sudden great interest in epidemiological modelling needed to be coordinated to provide much-needed support, and to limit the burden on epidemiological modellers already very stretched for time. In this paper we describe three initiatives set up in the UK in spring 2020 to coordinate the mathematical sciences research community in supporting mathematical modelling of COVID-19. Each initiative had different primary aims and worked to maximise synergies between the various projects. We reflect on the lessons learnt, highlighting the key roles of pre-existing research collaborations and focal centres of coordination in contributing to the success of these initiatives. We conclude with recommendations about important ways in which the scientific research community could be better prepared for future pandemics. This manuscript was submitted as part of a theme issue on “Modelling COVID-19 and Preparedness for Future Pandemics”. © 2022 The Author(s)

关键词： COVID-19 Knowledge exchange Mathematical modelling Research co-ordination

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Women ofSignificance?

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Significance 2022年第3期19卷 16-20页

作者： Dr Karen Lamb Jessica Kasza Dr Sophie Calabretto Dr Rushani Wijesuriya Dr Linda McIver Biostatistician at the University of Melbourne a member of the SSA Equity Diversity & Inclusivity committee and joined theSignificanceEditorial Board in 2021. Associate Professor Biostatistician at Monash University and president of the SSA. In that role she is keen to ensure that the SSA is diverse welcoming representative and inclusive. Applied mathematician and science writer an honorary senior lecturer in applied mathematics at Macquarie University and an honorary associate professor in the Aerospace & Computational Engineering (ACE) Research Group at the University of Leicester. Early-career biostatistician working across the University of Melbourne and the Murdoch Children's Research Institute. She is also a member of the SSA's Equity Diversity & Inclusivity committee. Founder and executive director of the Australian Data Science Education Institute a charity dedicated to building the data science and data literacy skills of all students.

Significance bills itself as “a magazine about statistics and data science, written by experts for everyone”. But too few of its featured experts are women, as an analysis by Karen Lamb, Jessica Kasza, Sophie Calabr...

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Figuring Out Gas & Galaxies In Enzo (FOGGIE). IV. The stochasticity of ram pressure stripping in galactic halos

arXiv

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arXiv 2020年

作者： Simons, Raymond C. Peeples, Molly S. Tumlinson, Jason O’Shea, Brian W. Smith, Britton D. Corlies, Lauren Lochhaas, Cassandra Zheng, Yong Augustin, Ramona Prasad, Deovrat Snyder, Gregory F. Tollerud, Erik Space Telescope Science Institute 3700 San Martin Drive BaltimoreMD21218 United States Department of Physics & Astronomy Johns Hopkins University 3400 N. Charles Street BaltimoreMD21218 United States Department of Computational Mathematics Science and Engineering Department of Physics and Astronomy National Superconducting Cyclotron Laboratory Michigan State University Royal Observatory University of Edinburgh United Kingdom Rubin Observatory Project Office 950 N. Cherry Ave. TucsonAZ85719 United States Department of Astronomy University of California BerkeleyCA94720 United States Miller Institute for Basic Research in Science University of California BerkeleyCA94720 United States

We study ram pressure stripping in simulated Milky Way–like halos at z ≥ 2 from the Figuring Out Gas & Galaxies In Enzo (FOGGIE) project. These simulations reach exquisite resolution in their circumgalactic medium (CGM) gas owing to FOGGIE’s novel refinement scheme. The CGM of each halo spans a wide dynamic range in density and velocity over its volume—roughly 6 dex and 1000 km s−1, respectively—translating into a 5 dex range in ram pressure imparted to interacting satellites. The ram pressure profiles of the simulated CGM are highly stochastic, owing to kpc-scale variations of the density and velocity fields of the CGM gas. As a result, the efficacy of ram pressure stripping depends strongly on the specific path a satellite takes through the CGM. The ram-pressure history of a single satellite is generally unpredictable and not well correlated with its approach vector with respect to the host galaxy. The cumulative impact of ram pressure on the simulated satellites is dominated by only a few short strong impulses—on average, 90% of the total surface momentum gained through ram pressure is imparted in 20% or less of the total orbital time. These results reveal an erratic mode of ram pressure stripping in Milky-Way like halos at high redshift—one that is not captured by a smooth spherically-averaged model of the circumgalactic medium. Copyright © 2020, The Authors. All rights reserved.

关键词： Galaxies

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AdS3 Einstein Gravity and Boundary Description: Pedagogical Review

arXiv

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arXiv 2023年

作者： Ma, Chen-Te Department of Physics and Astronomy Iowa State University AmesIA50011 United States Asia Pacific Center for Theoretical Physics Pohang University of Science and Technology Gyeongsangbuk-do Pohang37673 Korea Republic of Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University Guangdong Guangzhou510006 China School of Physics and Telecommunication Engineering South China Normal University Guangdong Guangzhou510006 China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing Center South China Normal University Guangzhou510006 China The Laboratory for Quantum Gravity and Strings Department of Mathematics and Applied Mathematics University of Cape Town Private Bag Rondebosch7700 South Africa

We review the various aspects of the 3D Einstein gravity theory with a negative cosmological constant and its boundary description. We also explore its connections to CFTs, modular symmetry, and holography. It is worth noting that this particular theory is topological in nature, which means that all the physical degrees of freedom are located on the boundary. Additionally, we can derive the boundary description on a torus, which takes the form of a 2D Schwarzian theory. This observation suggests that the relevant degrees of freedom for the theory can be described using this 2D theory. Because of the renormalizability of the 3D gravity theory, one can probe the quantum regime. This suggests that it is possible to investigate quantum phenomena. Unlike the conventional CFTs, when considering the AdS3 background, the boundary theory loses modular symmetry. This represents a departure from the usual behavior of CFT and is quite intriguing. The Weyl transformation induces anomaly in CFTs, and we indicate that applying this transformation to the 2D Schwarzian theory leads to similar results. Summing over all geometries with the asymptotic AdS3 boundary condition is equivalent to summing over a modular group. The partition function is one-loop exact and therefore an analytical expression from the summation. This theory holds potential applications in Quantum Information and is a recurring theme in the study of holography, where gravitational theories are connected with CFTs. Copyright © 2023, The Authors. All rights reserved.

关键词： Holography

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Measuring fairness preferences is important for artificial intelligence in health care

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The Lancet Digital Health 2024年第5期6卷 e302-e304页

作者： Näher, Anatol-Fiete Krumpal, Ivar Antão, Esther-Maria Ong, Erika Rojo, Marina Kaggwa, Fred Balzer, Felix Celi, Leo Anthony Braune, Katarina Wieler, Lothar H Agha-Mir-Salim, Louis Digital Global Public Health Hasso Plattner Institute for Digital Engineering University of Potsdam Potsdam14482 Germany Institute of Medical Informatics Charité–Universitätsmedizin Berlin Berlin Germany Faculty of Social Science and Philosophy University of Leipzig Leipzig Germany College of Medicine University of the Philippines Manila Philippines Department of Public Health School of Medicine University of Buenos Aires Buenos Aires Argentina Department of Computer Science Faculty of Computing and Informatics Mbarara University of Science and Technology Mbarara Uganda Laboratory for Computational Physiology Massachusetts Institute of Technology CambridgeMA United States Division of Pulmonary Critical Care and Sleep Medicine Beth Israel Deaconess Medical Center BostonMA United States Department of Biostatistics Harvard T H Chan School of Public Health BostonMA United States

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Quantifying Quantum Entanglement in Two-Qubit Mixed State from Connected Correlator

arXiv

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arXiv 2022年

作者： Guo, Xingyu Ma, Chen-Te Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum Matter South China Normal University Guangdong Guangzhou510006 China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing Center South China Normal University Guangdong Guangzhou510006 China Department of Physics and Astronomy Iowa State University AmesIA50011 United States Asia Pacific Center for Theoretical Physics Pohang University of Science and Technology Gyeongsangbuk-do Pohang37673 Korea Republic of School of Physics and Telecommunication Engineering South China Normal University Guangdong Guangzhou510006 China The Laboratory for Quantum Gravity and Strings Department of Mathematics and Applied Mathematics University of Cape Town Private Bag Rondebosch7700 South Africa

Our study employs a connected correlation matrix to quantify Quantum Entanglement. The matrix encompasses all necessary measures for assessing the degree of entanglement between particles. We begin with a three-qubit state and involve obtaining a mixed state by performing partial tracing over one qubit. Our goal is to exclude the non-connected sector by focusing on the connected correlation. This suggests that the connected correlation is deemed crucial for capturing relevant entanglement degrees. The study classifies mixed states and observes that separable states exhibit the lowest correlation within each class. We demonstrate that the entanglement measure monotonically increases concerning the correlation measure. This implies that connected correlation serves as an effective measure of Quantum Entanglement. Finally, our proposal suggests that interpreting Quantum Entanglement from a local perspective is possible. The observable is described as a vector with locality but violates freedom of choice. Copyright © 2022, The Authors. All rights reserved.

关键词： Quantum entanglement

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[email protected] , an ecosystem of virtual environments and tools for realistic indoor robotic simulation

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Expert Systems with Applications 2022年 208卷

作者： David Fernandez-Chaves Jose-Raul Ruiz-Sarmiento Alberto Jaenal Nicolai Petkov Javier Gonzalez-Jimenez Machine Perception and Intelligent Robotics group (MAPIR) Department of System Engineering and Automation Biomedical Research Institute of Malaga (IBIMA) University of Malaga Spain Johann Bernoulli Institute of Mathematics and Computing Science University of Groningen The Netherlands

Simulations and synthetic datasets have historically empower the research in different service robotics-related problems, being revamped nowadays with the utilization of rich virtual environments. However, with their use, special attention must be paid so the resulting algorithms are not biased by the synthetic data and can generalize to real world conditions. These aspects are usually compromised when the virtual environments are manually designed. This article presents [email protected] , an ecosystem of virtual environments and tools that allows for the management of realistic virtual environments where robotic simulations can be performed. Here “realistic” means that those environments have been designed by mimicking the rooms’ layout and objects appearing in 30 real houses, hence not being influenced by the designer’s knowledge. The provided virtual environments are highly customizable (lighting conditions, textures, objects’ models, etc.), accommodate meta-information about the elements appearing therein (objects’ types, room categories and layouts, etc.), and support the inclusion of virtual service robots and sensors. To illustrate the possibilities of [email protected] we show how it has been used to collect a synthetic dataset, and also exemplify how to exploit it to successfully face two service robotics-related problems: semantic mapping and appearance-based localization.

关键词： Virtual environments Robotic simulation Service robots Semantic maps Robotic dataset Unity

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NAVAL COASTAL SYSTEMS LABORATORY - UNIQUE INSITU TEST AND EVALUATION SITE

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NAVAL ENGINEERS JOURNAL 1978年第2期90卷 119-129页

作者： JOLLIFF, JV CALLAHAN, CM USN Capt. James V. Jolliff USNgraduated from the U. S. Naval Academy in 1954. Following graduation he served in the USS S. N. Moore (DD—747) and USS Cimarron (AO—22). He received his MS degrees in Naval Architecture from Webb Institute of Naval Architecture and in Financial Management from The George Washington University. He culminated his education at The Catholic University of America where he was awarded his Doctorate in Ocean Engineering in 1972. Capt. Jolliff has served in Naval Shipyards as Ship Superintendent Assistant Repair Officer and Assistant Planning & Estimating Superintendent and as such was primarily concerned with the repair and conversion of U. S. Navy skips. In addition he has served as Maintenance Officer Staff of Commander Mine Force U. S. Pacific Fleet as Co—Chairman of the Naval Engineering Division Engineering Department U. S. Naval Academy and as CV Design Manager in the Advanced Concepts Division and as Head Ship Survivability Office Naval Ship Engineering Center. An active member of ASNE since 1966 he has served as a member of the National Council and is currently the Chairman of the Journal Committee. He has had several papers presented at ASNE Day and published in the Journal and in 1976 was one of the recipients of the ASNE President's Award. At the present time he is assigned as the Commanding Officer Naval Coastal Systems Laboratory (NCSL) Panama City Fla. Mr. Casville M. Callahanis a native of Southwest Virginia where he attended Elementary and Secondary School prior to his three year's service in the U. S. Navy during World War II. He graduated from Lincoln Memorial University Harrogate Tenn. in 1950 receiving his BS degree in Mathematics. In 1952 he received his MS degree in Mathematics from Auburn University Auburn Ala. and taught mathematics at Lincoln Memorial University and at Florida State University Tallahassee Fla. prior to joining the staff of the Mine Defense Laboratory in 1955. He has progressed through a variety of assignments as the Labo

Test and Evaluation have become paramount in today's Department of Defense acquisition process. Therefore, the U. S. Navy requires both private and public facilities to accomplish the final goals of the “Fly before Buy” concept. Such a facility exists at the Naval Coastal Systems Laboratory (NCSL); an integral part of the Chief of Naval Material's, Director of Navy Laboratories organization. This paper briefly addresses the Laboratory, its mission, and its history. This is followed by an in—depth facilities overview in order to create an understanding of the slow but steady evolution of NCSL's unique fixed facilities. These facilities, when coupled to the local natural environment, provide a unique in situ test and evaluation capability which is unequalled in the United States for assessing seagoing coastal systems. Of prime consideration is the Range Date Acquisition Center (RADAC) and Its ancillary subsystems for tracking, environmental monitoring, communications, and post run analysis. The paper is concluded with a discussion of both past and present use of the aforementioned facilities with an emphasis on user acceptance and future potential growth.

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Recollision of excited electron in below-threshold nonsequential double ionization

arXiv

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arXiv 2021年

作者： Hao, Xiaolei Bai, Yuxing Li, Chan Zhang, Jingyu Li, Weidong Yang, Weifeng Liu, MingQing Chen, Jing Institute of Theoretical Physics Department of Physics State Key Laboratory of Quantum Optics and Quantum Optics Devices Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan030006 China Department of Physics College of Science Shantou University Shantou Guangdong515063 China Institute of Applied Physics and Computational Mathematics P. O. Box 8009 Beijing100088 China Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Advanced Material Diagnostic Technology College of Engineering Physics Shenzhen Technology University Shenzhen518118 China

Consensus has been reached that recollision, as the most important post-tunneling process, is responsible for nonsequential double ionization process in intense infrared laser field, however, its effect has been restricted to interaction between the first ionized electron and the residual univalent ion so far. Here we identify the key role of recollision between the second ionized electron and the divalent ion in the below-threshold nonsequential double ionization process by introducing a Coulomb-corrected quantum-trajectories method, which enables us to well reproduce the experimentally observed cross-shaped and anti-correlated patterns in correlated two-electron momentum distributions, and also the transition between these two patterns. Being significantly enhanced relatively by the recapture process, recolliding trajectories of the second electron excited by the first- or third-return recolliding trajectories of the first electron produce the cross-shaped or anti-correlated distributions, respectively. And the transition is induced by the increasing contribution of the third return with increasing pulse duration. Our work provides new insight into atomic ionization dynamics and paves the new way to imaging of ultrafast dynamics of atoms and molecules in intense laser field. Copyright © 2021, The Authors. All rights reserved.

关键词： Ionization of gases

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