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Strong Converse Magnetoelectric Effect in a Composite of Weakly Ferromagnetic Iron Borate and Ferroelectric Lead Zirconate Titanate

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Physical Review Applied 2020年第3期14卷 034039-034039页

作者： M. Popov Y. Liu V.L. Safonov I.V. Zavislyak V. Moiseienko P. Zhou Jiayu Fu Wei Zhang Jitao Zhang Y. Qi Tianjin Zhang T. Zhou P.J. Shah M.E. McConney M.R. Page G. Srinivasan Physics Department Oakland University Rochester Michigan 48309 USA Faculty of Radiophysics Electronics and Computer Systems Taras Shevchenko National University of Kyiv Kyiv 01601 Ukraine Department of Materials Science and Engineering Hubei University Wuhan 430062 People’s Republic of China Materials and Manufacturing Directorate Air Force Research Laboratory Wright-Patterson Air Force Base Dayton Ohio 45433 USA College of Electronics and Information Hangzhou Dianzi University Hangzhou 310018 People’s Republic of China College of Electrical and Information Engineering Zhengzhou University of Light Industry Zhengzhou 450002 People’s Republic of China

This report is on a model and experiment on the nature of mechanical-strain-mediated converse magnetoelectric (CME) effect in a composite of single-crystal iron borate, a canted antiferromagnet with a weak ferromagnetic moment, and ferroelectric lead zirconate titanate (PZT). The piezoelectric strain generated in PZT by an electric field E manifested as a shift in the quasiferromagnetic resonance (FMR) field in iron borate due to strong magnetoelastic interactions. The CME interaction strength determined from data on field shift in FMR versus E is 46–54 MHz cm/kV at 5.5–6.5 GHz. The strength of the CME is comparable to values reported for composites of ferrimagnetic oxides and PZT. A model that considers the effect of piezoelectric deformation on magnetic order parameters and magnetic resonance in iron borate is proposed for the CMEs in the composite and estimated ME coupling coefficients are in good agreement with data. The E tunability of the high-frequency AFMR mode at about 300 GHz is estimated to be on the order of 1.7 MHz kV/cm and is very small relative to the quasi-FMR mode. Composites of iron borate and ferroelectrics are very attractive for use in dual electric field and magnetic field tunable signal processing devices due to strong CME interactions and the need for a rather small bias magnetic field compared with traditional ferrimagnetic oxide based devices.

关键词： Magnetic coupling Magnetoelectric effect Multiferroics Strain Antiferromagnets Bilayer films Ferroelectrics Transition metal oxides

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Initial ASEAN digital security and interoperability standard proposal

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AIP Conference Proceedings 2023年第1期2739卷

作者： Sangsuree Vasupongayya Gunawan Hutagalung Obrina Candra Chalee Vorakulpipat Doni Purnomo Parinda Wattanasri Eko Supriyanto Shukor Abd Razak Othman Ibrahim Anazida Zainal Sri Devi Ravana Hiep Cong Pham Tharith Sriv Daw Khin Myo Su Mora Hertanto Agus Winarno Prabaswari Raden Muhammad Taufik Yuniantoro Badrus Zaman Fatmawati Retna Apsari Yutika Amelia Effendi Norjihan Abdul Ghani Zarina Shukur Hamidah Ibrahim Nur Izura Udzir Marnel Peradilla Jude Michael Teves Nestor Michael Tiglao Cenon Alfonso Pg Emeroylariffion Abas Mueen Uddin Agustin Kusumayati Brian Sri Prahastuti Department of Computer Engineering Faculty of Engineering Prince of Songkla University Hatyai Songkhla 90110 THAILAND Directorate General of Post and Information Technology Ministry of Communication and Information Technology Jakarta INDONESIA Politeknik Siber dan Sandi Negara National Cyber & Crypto Agency (BSSN) Depok West Java INDONESIA Information Security Research Team at National Electronics and Computer Technology Center Bangkok THAILAND National Standardization Agency of Indonesia Jakarta INDONESIA Department of Disease Control Ministry of Public Health Mueang Nonthaburi Nonthaburi THAILAND School of Biomedical Engineering and Health Sciences Faculty of Engineering Universiti Teknologi Malaysia Johor Bahru Johor MALAYSIA IJN-UTM Cardiovascular Engineering Center Institute of Human Centered Engineering Universiti Teknologi Malaysia Johor Bahru Johor MALAYSIA School of Computing Faculty of Engineering Universiti Teknologi Malaysia Johor Bahru Johor MALAYSIA Faculty of Computer Science & Information Technology Universiti Malaya Kuala Lumpur MALAYSIA RMIT University Vietnam Ho Chi Minh City VIETNAM Royal University of Phnom Penh Phnom Penh CAMBODIA Yangon University of Economics Yangon MYANMAR Agency for the Assessment and Application of Technology (BPPT) Jakarta INDONESIA Faculty of Science and Technology Universitas Airlangga Surabaya East Java INDONESIA Faculty of Advanced Technology and Multidiscipline Universitas Airlangga Surabaya East Java INDONESIA Centre for Cyber Security Universiti Kebangsaan Malaysia Bangi Selangor MALAYSIA Faculty of Computer Science and Information Technology Universiti Putra Malaysia Serdang Selangor MALAYSIA Computer Technology Department College of Computer Studies De La Salle University Manila PHILIPPINES Software Technology Department College of Computer Studies De La Salle University Manila PHILIPPINES Electrical and Electronics Engineering Institute University of the Philippines Diliman Quezon City P

In this work, the result of the initial attempt to propose an Association of Southeast Asian Nations (ASEAN) digital security and interoperability standard to support the mobility among ASEAN countries is presented. Literature reviews on existing coronavirus disease 2019 (COVID-19) related digital technologies of six ASEAN member countries are conducted. Several concerns related to creating/implementing the ASEAN digital security and interoperability standard are discussed including the technology accessing concern, the data security and privacy concern, and the data interoperability and availability concern. The proposed solution toward creating an ASEAN digital security and interoperability standard is then presented. To evaluate the proposed solution, a survey has been conducted on representatives of nine ASEAN countries on four main issues including the security standards and requirements, the interoperability standard and requirements, the certifications, and the implementation challenges. According to the survey and the discussion, seven recommendations were proposed toward creating an ASEAN digital security and interoperability standard. First, each country collects and maintains the data of its own citizens and also provides a method to authenticate and access the data by authorized requests. Second, QR code standard or ASEAN QR code standard must be agreed upon so that it can be authenticated and verified by ASEAN countries. Third, health risk assessment must be agreed upon to be used. Forth, the security standard, the data, the data format and the exchange protocol must be agreed upon at the ASEAN policy level while adoption of international standards as an implementation guideline will ease of the process and neutralize different requirements from various countries. Fifth, any accountability of incidents must be agreed upon at the ASEAN policy level. Sixth, certification might be extended to certification of risk assessment for organizations, products or

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PINPOINT: Efficient and effective resource isolation for mobile security and privacy

arXiv

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arXiv 2019年

作者： Ratazzi, Paul Bommisetti, Ashok Ji, Nian Du, Wenliang Information Directorate Air Force Research Laboratory RomeNY United States Dept. of Electrical Engineering & Computer Science Syracuse University SyracuseNY United States

Virtualization is frequently used to isolate untrusted processes and control their access to sensitive resources. However, isolation usually carries a price in terms of less resource sharing and reduced inter-process communication. In an open architecture such as Android, this price and its impact on performance, usability, and transparency must be carefully considered. Although previous efforts in developing general-purpose isolation solutions have shown that some of these negative side-effects can be mitigated, doing so involves overcoming significant design challenges by incorporating numerous additional platform complexities not directly related to improved security. Thus, the general purpose solutions become inefficient and burdensome if the end-user has only specific security goals. In this paper, we present PINPOINT, a resource isolation strategy that forgoes general-purpose solutions in favor of a "building block" approach that addresses specific end-user security goals. PINPOINT embodies the concept of Linux Namespace lightweight isolation, but does so in the Android Framework by guiding the security designer towards isolation points that are contextually close to the resource(s) that need to be isolated. This strategy allows the rest of the Framework to function fully as intended, transparently. We demonstrate our strategy with a case study on Android System Services, and show four applications of PINPOINTed system services functioning with unmodified market apps. Our evaluation results show that practical security and privacy advantages can be gained using our approach, without inducing the problematic side-effects that other general-purpose designs must address. Copyright © 2019, The Authors. All rights reserved.

关键词： Mobile security

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APPLR: Adaptive planner parameter learning from reinforcement

arXiv

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arXiv 2020年

作者： Xu, Zifan Dhamankar, Gauraang Nair, Anirudh Xiao, Xuesu Warnell, Garrett Liu, Bo Wang, Zizhao Stone, Peter Department of Physics University of Texas at Austin AustinTX78712 United States Computer Science University of Texas at Austin AustinTX78712 United States Mathematics University of Texas at Austin AustinTX78712 United States Electrical and Computer Engineering University of Texas at Austin AustinTX78712 United States Computational and Information Sciences Directorate Army Research Laboratory AdelphiMD20783 United States

Classical navigation systems typically operate using a fixed set of hand-picked parameters (e.g. maximum speed, sampling rate, inflation radius, etc.) and require heavy expert re-tuning in order to work in new environments. To mitigate this requirement, it has been proposed to learn parameters for different contexts in a new environment using human demonstrations collected via teleoperation. However, learning from human demonstration limits deployment to the training environment, and limits overall performance to that of a potentially-suboptimal demonstrator. In this paper, we introduce APPLR, Adaptive Planner Parameter Learning from Reinforcement, which allows existing navigation systems to adapt to new scenarios by using a parameter selection scheme discovered via reinforcement learning (RL) in a wide variety of simulation environments. We evaluate APPLR on a robot in both simulated and physical experiments, and show that it can outperform both a fixed set of hand-tuned parameters and also a dynamic parameter tuning scheme learned from human demonstration. Copyright © 2020, The Authors. All rights reserved.

关键词： Navigation systems

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Variational Policy Gradient Method for Reinforcement Learning with General Utilities

arXiv

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arXiv 2020年

作者： Zhang, Junyu Koppel, Alec Bedi, Amrit Singh Szepesvari, Csaba Wang, Mengdi Department of Industrial and Systems Engineering University of Minnesota MinneapolisMN55455 United States Computational and Information Sciences Directorate US Army Research Laboratory AdelphiMD20783 United States Department of Computer Science DeepMind University of Alberta PrincetonNJ08544 United States Department of Electrical Engineering Center for Statistics and Machine Learning Princeton University Deepmind PrincetonNJ08544 United States

In recent years, reinforcement learning (RL) systems with general goals beyond a cumulative sum of rewards have gained traction, such as in constrained problems, exploration, and acting upon prior experiences. In this paper, we consider policy optimization in Markov Decision Problems, where the objective is a general concave utility function of the state-action occupancy measure, which subsumes several of the aforementioned examples as special cases. Such generality invalidates the Bellman equation. As this means that dynamic programming no longer works, we focus on direct policy search. Analogously to the Policy Gradient Theorem Sutton et al. (2000) available for RL with cumulative rewards, we derive a new Variational Policy Gradient Theorem for RL with general utilities, which establishes that the parametrized policy gradient may be obtained as the solution of a stochastic saddle point problem involving the Fenchel dual of the utility function. We develop a variational Monte Carlo gradient estimation algorithm to compute the policy gradient based on sample paths. We prove that the variational policy gradient scheme converges globally to the optimal policy for the general objective, though the optimization problem is nonconvex. We also establish its rate of convergence of the order O(1/t) by exploiting the hidden convexity of the problem, and proves that it converges exponentially when the problem admits hidden strong convexity. Our analysis applies to the standard RL problem with cumulative rewards as a special case, in which case our result improves the available convergence rate. Copyright © 2020, The Authors. All rights reserved.

关键词： Dynamic programming

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Controlled-Phase Gate Using Dynamically Coupled Cavities and Optical Nonlinearities

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Physical Review Letters 2020年第16期124卷 160501-160501页

作者： Mikkel Heuck Kurt Jacobs Dirk R. Englund DTU Fotonik Technical University of Denmark Building 343 2800 Kongens Lyngby Denmark Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge Massachusetts 02139 USA U.S. Army Research Laboratory Computational and Information Sciences Directorate Adelphi Maryland 20783 USA Department of Physics University of Massachusetts at Boston Boston Massachusetts 02125 USA Hearne Institute for Theoretical Physics Louisiana State University Baton Rouge Louisiana 70803 USA

We show that relatively simple integrated photonic circuits have the potential to realize a high fidelity deterministic controlled-phase gate between photonic qubits using bulk optical nonlinearities. The gate is enabled by converting travelling continuous-mode photons into stationary cavity modes using strong classical control fields that dynamically change the effective cavity-waveguide coupling rate. This architecture succeeds because it reduces the wave packet distortions that otherwise accompany the action of optical nonlinearities [J. Shapiro, Phys. Rev. A 73, 062305 (2006); J. Gea-Banacloche, Phys. Rev. A 81, 043823 (2010)]. We show that high-fidelity gates can be achieved with self-phase modulation in χ(3) materials as well as second-harmonic generation in χ(2) materials. The gate fidelity asymptotically approaches unity with increasing storage time for an incident photon wave packet with fixed duration. We also show that dynamically coupled cavities enable a trade-off between errors due to loss and wave packet distortion. Our proposed architecture represents a new approach to practical implementation of quantum gates that is room-temperature compatible and only relies on components that have been individually demonstrated.

关键词： Integrated optics Optical quantum information processing Quantum gates Second order nonlinear optical processes Third order nonlinear optical processes

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Photon-photon interactions in dynamically coupled cavities

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Physical Review A 2020年第4期101卷 042322-042322页

We study theoretically the interaction between two photons in a nonlinear cavity. The photons are absorbed into the cavity by an effective tuning of its input-output coupling via external control of a coupling to a second, strongly output-coupled cavity mode. Such “dynamically coupled” cavities, which can be implemented using bulk χ(2) and χ(3) nonlinearities, enable incoming photon wave packets to be absorbed into the cavity with high fidelity when the duration of the control is similar to that of the wave packets. Further, this configuration can be used to avoid limitations in the photon-photon interaction time set by the delay-bandwidth product of passive cavities and enables the elimination of wave-packet distortions caused by dispersive cavity transmission and reflection. We consider three kinds of nonlinearities, two arising from χ(2) and χ(3) materials and one due to an interaction with a two-level emitter. To analyze the input and output of few-photon wave packets, we use a Schrödinger-picture formalism in which traveling-wave fields are discretized into infinitesimal time bins. We suggest that dynamically coupled cavities provide a very useful tool for improving the performance of quantum devices relying on cavity-enhanced light-matter interactions such as single-photon sources and atomlike quantum memories with photon interfaces. As an example, we present simulation results showing that high-fidelity two-qubit entangling gates may be constructed using any of the considered nonlinear interactions.

关键词： Integrated optics Optical quantum information processing Quantum gates Second order nonlinear optical processes Third order nonlinear optical processes

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Trajectory synthesis for a UAV swarm to perform resilient requirement-aware surveillance: A smart grid-based study

arXiv

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arXiv 2019年

作者： Ashiqur Rahman, M. Masum, Rahat Anderson, Matthew Drager, Steven L. Department of Electrical and Computer Engineering Florida International University MiamiFL United States Department of Computer Science Tennessee Tech University CookevilleTN United States Air Force Research Laboratory Information Directorate RomeNY United States

A smart grid is a widely distributed engineering system with overhead transmission lines. Physical damage to these power lines, from natural calamities or technical failures, will disrupt the functional integrity of the grid. To ensure the continuation of the grid's operational flow when those phenomena happen, the grid operator must immediately take steps to nullify the impacts and repair the problems, even if those occur in hardly-reachable remote areas. Emerging unmanned aerial vehicles (UAVs) show great potential to replace traditional human patrols for regularly monitoring critical situations involving the safety of the grid. The critical lines can be monitored by a fleet of UAVs to ensure a resilient surveillance system. The proposed approach considers the n-1 contingency analysis to find the criticality of a transmission line. We propose a formal framework that verifies whether a given set of UAVs (i.e., a UAV swarm) can perform continuous surveillance of the grid satisfying various requirements, particularly the monitoring and resiliency specifications. The verification process ultimately provides a trajectory plan for the UAVs, including the refueling schedules. The resiliency requirement of inspecting a point on a line is expressed in terms of a k−property specifying that if k UAVs fail or compromised still there is a UAV to collect the data at the point within on time. We evaluate the proposed framework on synthetic data based on various IEEE test bus systems. Copyright © 2019, The Authors. All rights reserved.

关键词： Unmanned aerial vehicles (UAV)

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BigNeuron: a resource to benchmark and predict performance of algorithms for automated tracing of neurons in light microscopy datasets

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Nature methods 2023年第6期20卷 824-835页

作者： Linus Manubens-Gil Zhi Zhou Hanbo Chen Arvind Ramanathan Xiaoxiao Liu Yufeng Liu Alessandro Bria Todd Gillette Zongcai Ruan Jian Yang Miroslav Radojević Ting Zhao Li Cheng Lei Qu Siqi Liu Kristofer E Bouchard Lin Gu Weidong Cai Shuiwang Ji Badrinath Roysam Ching-Wei Wang Hongchuan Yu Amos Sironi Daniel Maxim Iascone Jie Zhou Erhan Bas Eduardo Conde-Sousa Paulo Aguiar Xiang Li Yujie Li Sumit Nanda Yuan Wang Leila Muresan Pascal Fua Bing Ye Hai-Yan He Jochen F Staiger Manuel Peter Daniel N Cox Michel Simonneau Marcel Oberlaender Gregory Jefferis Kei Ito Paloma Gonzalez-Bellido Jinhyun Kim Edwin Rubel Hollis T Cline Hongkui Zeng Aljoscha Nern Ann-Shyn Chiang Jianhua Yao Jane Roskams Rick Livesey Janine Stevens Tianming Liu Chinh Dang Yike Guo Ning Zhong Georgia Tourassi Sean Hill Michael Hawrylycz Christof Koch Erik Meijering Giorgio A Ascoli Hanchuan Peng Institute for Brain and Intelligence Southeast University Nanjing China. Microsoft Corporation Redmond WA USA. Tencent AI Lab Bellevue WA USA. Computing Environment and Life Sciences Directorate Argonne National Laboratory Lemont IL USA. Kaya Medical Seattle WA USA. University of Cassino and Southern Lazio Cassino Italy. Center for Neural Informatics Structures and Plasticity Krasnow Institute for Advanced Study George Mason University Fairfax VA USA. Faculty of Information Technology Beijing University of Technology Beijing China. Beijing International Collaboration Base on Brain Informatics and Wisdom Services Beijing China. Nuctech Netherlands Rotterdam the Netherlands. Janelia Research Campus Howard Hughes Medical Institute Ashburn VA USA. Department of Electrical and Computer Engineering University of Alberta Edmonton Alberta Canada. Ministry of Education Key Laboratory of Intelligent Computation and Signal Processing Anhui University Hefei China. Paige AI New York NY USA. Scientific Data Division and Biological Systems and Engineering Division Lawrence Berkeley National Lab Berkeley CA USA. Helen Wills Neuroscience Institute and Redwood Center for Theoretical Neuroscience UC Berkeley Berkeley CA USA. RIKEN AIP Tokyo Japan. Research Center for Advanced Science and Technology (RCAST) The University of Tokyo Tokyo Japan. School of Computer Science University of Sydney Sydney New South Wales Australia. Texas A&M University College Station TX USA. Cullen College of Engineering University of Houston Houston TX USA. Graduate Institute of Biomedical Engineering National Taiwan University of Science and Technology Taipei Taiwan. National Centre for Computer Animation Bournemouth University Poole UK. PROPHESEE Paris France. Department of Neuroscience Columbia University New York NY USA. Mortimer B. Zuckerman Mind Brain Behavior Institute Columbia University New York NY USA. Department of Computer Science Northern Illinois Universit

BigNeuron is an open community bench-testing platform with the goal of setting open standards for accurate and fast automatic neuron tracing. We gathered a diverse set of image volumes across several species that is representative of the data obtained in many neuroscience laboratories interested in neuron tracing. Here, we report generated gold standard manual annotations for a subset of the available imaging datasets and quantified tracing quality for 35 automatic tracing algorithms. The goal of generating such a hand-curated diverse dataset is to advance the development of tracing algorithms and enable generalizable benchmarking. Together with image quality features, we pooled the data in an interactive web application that enables users and developers to perform principal component analysis, t-distributed stochastic neighbor embedding, correlation and clustering, visualization of imaging and tracing data, and benchmarking of automatic tracing algorithms in user-defined data subsets. The image quality metrics explain most of the variance in the data, followed by neuromorphological features related to neuron size. We observed that diverse algorithms can provide complementary information to obtain accurate results and developed a method to iteratively combine methods and generate consensus reconstructions. The consensus trees obtained provide estimates of the neuron structure ground truth that typically outperform single algorithms in noisy datasets. However, specific algorithms may outperform the consensus tree strategy in specific imaging conditions. Finally, to aid users in predicting the most accurate automatic tracing results without manual annotations for comparison, we used support vector machine regression to predict reconstruction quality given an image volume and a set of automatic tracings.

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Generalized WKB theory for electron tunneling in gapped α−T3 lattices

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Physical Review B 2021年第16期103卷 165429-165429页

作者： Nicholas Weekes Andrii Iurov Liubov Zhemchuzhna Godfrey Gumbs Danhong Huang Department of Physics and Computer Science Medgar Evers College of City University of New York Brooklyn New York 11225 USA Department of Information Systems and Cybersecurity Grove School of Engineering The City College of New York 275 Convent Avenue New York New York 10031 USA Department of Physics and Astronomy Hunter College of the City University of New York 695 Park Avenue New York New York 10065 USA Donostia International Physics Center (DIPC) P de Manuel Lardizabal 4 20018 San Sebastian Basque Country Spain Space Vehicles Directorate US Air Force Research Laboratory Kirtland Air Force Base New Mexico 87117 USA Center for High Technology Materials University of New Mexico 1313 Goddard SE Albuquerque New Mexico 87106 USA

We generalize Wentzel-Kramers-Brillouin (WKB) semiclassical equations for pseudospin-1 α−T3 materials with arbitrary hopping parameter 0<α<1, which includes the dice lattice and graphene as two limiting cases. In conjunction with a series-expansion method in powers of Planck constant ℏ, we acquired and solved a system of recurrent differential equations for semiclassical electron wave functions in α−T3. Making use of these obtained wave functions, we analyzed the physics-related mechanism and quantified the transmission of pseudospin-1 Dirac electrons across nonrectangular potential barriers in α−T3 materials with both zero and finite band gaps. Our studies reveal several unique features, including the way in which the electron transmission depends on the energy gap, the slope of the potential barrier profile and the transverse momentum of incoming electrons. Specifically, we have found a strong dependence of the obtained transmission amplitude on the geometry-phase ϕ=tan−1α of α−T3 lattices. We believe our current findings can be applied to Dirac cone-based tunneling transistors in ultrafast analog RF devices, as well as to tunneling-current control by a potential barrier through a one-dimensional array of scatters.

关键词： Ballistic transport Electronic structure Transport phenomena Semiclassical methods

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