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Journal of Vacuum Science & Technology B: Microelectronics Processing and Phenomena 1986年第2期4卷 523-524页

作者： D. C. Reynolds C. W. Litton K. K. Bajaj P. W. Yu Jasprit Singh P. J. Pearah W. T. Masselink T. Henderson J. Klem H. Morkoç AFWAL/AADR Wright–Patterson Air Force Base Ohio 45433 Wright State University Dayton Ohio 45435 Universal Energy Systems Inc. Dayton Ohio 45432 Department of Electrical and Computer Engineering and Coordinated Science Laboratory University of Illinois Urbana Illinois 61801

D. C. Reynolds, C. W. Litton, K. K. Bajaj, P. W. Yu, Jasprit Singh, P. J. Pearah, W. T. Masselink, T. Henderson, J. Klem, H. Morkoç; Summary Abstract: Optical p

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Securing data transfer in asynchronous transfer mode networks

Securing data transfer in asynchronous transfer mode network...

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IEEE Conference and Exhibition on Global Telecommunications (GLOBECOM)

作者： R.H. Deng Li Gong A.A. Lazar Institute of Systems Science National University of Singapore Singapore Computer Science Laboratory SRI International Inc. Menlo Park CA USA Department of Electrical Engineering and Center for Telecommunications Research Columbia University New York NY USA

Asynchronous transfer mode (ATM), which can provide integrated services of various media types and bit rates, is rapidly becoming the dominant technology for local and wide area information transport. In this paper we present a network security architecture for secure data transfer in ATM networks. The proposed architecture facilitates seamless integration of security services into the existing ATM architecture and conforms to the ATM B-ISDN PRM: security related signaling functionality, such as mutual end system authentication, establishment of security associations, and cryptographic key distributions are carried out in the control plane, while protection of user traffic is achieved by defining a data protection layer in the user plane.

关键词： Asynchronous transfer mode Data security Information security Protection Intserv networks Bit rate B-ISDN Authentication Cryptography Control systems

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Computation Methods for One Dimensional Bipolar Charge Injection

Computation Methods for One Dimensional Bipolar Charge Injec...

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IEEE Industry Applications Society Annual Meeting (IAS)

作者： Markus Zahn Lori Antis Jorge Mescua Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science Laboratory for Electromagnetic and Electronic Systems High Voltage Research Laboratory Cambridge MA 02139 M.I.T. Visiting Scientist (1984-85 academic year) from the University of North Carolina Charlotte

Kerr electro-optic field mapping measurements have shown strong space charge effects in high voltage stressed dielectrics, where the magnitude and sign of injected charge depends on electrode material. with appropriate choice of electrode material combinations and voltage polarity, it is possible to have uncharged, unipolar charged positive or negative, or bipolar charged dielectric. The bipolar homocharge case lowers the electric field at both electrodes due to space charge shielding and thus allows a higher voltage without breakdown. Charge transport analysis considers the general case of charge injection from both electrodes and solves for the time and space dependences of the electric field and charge distributions and the time dependences of the terminal voltage and current. This analysis extends earlier work by including non-equilibrium charge dissociation and recombination so that the effective ohmic conductivity is not constant but rather varies with time and position due to local net charge density. Specific cases discussed are the open circuit voltage decay of an initially charged capacitor, the charging and discharging by a Marx generator, and alternating voltage excitations.

关键词： Electrodes Trajectory Conductivity Electric fields Dielectrics Space charge Electric breakdown

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DSP Based Implementation of Multi Fault Signature Monitoring

DSP Based Implementation of Multi Fault Signature Monitoring

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Annual IEEE Conference on Applied Power Electronics Conference and Exposition (APEC)

作者： Bilal Akin Seung-deog Choi Mina M. Rahimian Hamid A. Toliyat C2000 Systems & Applications Group Texas Instruments Inc. Stafford TX USA Advanced Electric Machines & Power Electronics Laboratory Department of Electrical & Computer Engineering Texas A and M University College Station TX USA

The reference frame theory constitutes an essential aspect of electric machine analysis and control. In this study, apart from the conventional applications, it is reported that the reference frame theory approach (RFTA) can successfully be applied to real time fault diagnosis of electric machinery systems as a powerful tool to find the magnitude and phase quantities of fault signatures with good precision. Although it is possible to run RFTA for each fault signature consecutively, orthogonal PN (Pseudo Noise) code is proposed as an alternative method to detect more than one fault simultaneously. As the physical facts explaining the incipient fault mechanisms are studied for a long time, the motor fault signature frequencies and fault models are very well-known. Therefore, ignoring all other components, the proposed method focuses only on certain fault signatures in the current spectrum depending on the examined motor fault. Broken rotor bar and eccentricity faults are experimentally tested employing the TMS320F2812 digital signal processor (DSP) to prove the effectiveness of the proposed method. In this application, only the readily available drive hardware is used without employing additional components such as analog filters, signal conditioning board, external sensors, etc. The motor drive on-board DSP is utilized both for motor control and fault detection purposes providing instantaneous fault information. Being a model independent fault analyzer, this method can be applied to all multi-phase and single phase motors.

关键词： Digital signal processing Monitoring Motor drives Electric machines Real time systems Fault diagnosis Machinery electrical fault detection Frequency Rotors

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Technical report: Sensor-based reactive symbolic planning in partially known environments

arXiv

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arXiv 2017年

作者： Vasilopoulos, Vasileios Vega-Brown, William Arslan, Omur Roy, Nicholas Koditschek, Daniel E. Department of Mechanical Engineering and Applied Mechanics University of Pennsylvania PhiladelphiaPA19104 United States Computer Science and Artificial Intelligence Laboratory Massachusetts Institute of Technology CambridgeMA02139 United States Department of Electrical and Systems Engineering University of Pennsylvania PhiladelphiaPA19104 United States

This paper considers the problem of completing assemblies of passive objects in nonconvex environments, cluttered with convex obstacles of unknown position, shape and size that satisfy a specific separation assumption. A differential drive robot equipped with a gripper and a LIDAR sensor, capable of perceiving its environment only locally, is used to position the passive objects in a desired configuration. The method combines the virtues of a deliberative planner generating high-level, symbolic commands, with the formal guarantees of convergence and obstacle avoidance of a reactive planner that requires little onboard computation and is used online. The validity of the proposed method is verified both with formal proofs and numerical simulations. Copyright © 2017, The Authors. All rights reserved.

关键词： Optical radar

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A real-time maintenance scheduling policy in serial production lines

A real-time maintenance scheduling policy in serial producti...

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World Congress on Intelligent Control and Automation (WCICA)

作者： Lingbo Lu Yang Liu Jingshan Li Cindy Chang Stephan Biller Guoxian Xiao Department of Electrical and Computer Engineering University of Kentucky Lexington KY USA Department of Industrial Engineering University of Louisville Louisville KY USA Department of Industrial and Systems Engineering University of Wisconsin Madison Madison WI USA Department of Mechanical Engineering New York Institute of Technology Old Westbury NY USA Manufacturing Systems Research Laboratory General Motors Research and Development Center Warren MI USA

In this paper, we carry out a simulation study to integrate preventive maintenance scheduling policy with real-time production system analysis and workforce dispatching rule to investigate the impact of such a policy on system productivity. The preventive maintenance is triggered by the threshold of number of breakdowns and current up- and downstream buffer status, with the maintenance workforce being dispatched based on dynamic bottleneck policy. It is shown that the system performance can be improved by implementing such a real-time scheduling policy.

关键词： Electric breakdown

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Cyber-Security Knowledge Graph Generation by Hierarchical Nonnegative Matrix Factorization

arXiv

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arXiv 2024年

作者： Barron, Ryan Eren, Maksim E. Bhattarai, Manish Wanna, Selma Solovyev, Nicholas Rasmussen, Kim Alexandrov, Boian S. Nicholas, Charles Matuszek, Cynthia Theoretical Division Los Alamos National Laboratory Los Alamos United States Advanced Research in Cyber Systems Los Alamos National Laboratory Los Alamos United States Department of Computer Science and Electrical Engineering University of Maryland Baltimore CountyMD United States

Much of human knowledge in cybersecurity is encapsulated within the ever-growing volume of scientific papers. As this textual data continues to expand, the importance of document organization methods becomes increasingly crucial for extracting actionable insights hidden within large text datasets. Knowledge Graphs (KGs) serve as a means to store factual information in a structured manner, providing explicit, interpretable knowledge that includes domain-specific information from the cybersecurity scientific literature. One of the challenges in constructing a KG from scientific literature is the extraction of ontology from unstructured text. In this paper, we address this topic and introduce a method for building a multi-modal KG by extracting structured ontology from scientific papers. We demonstrate this concept in the cybersecurity domain. One modality of the KG represents observable information from the papers, such as the categories in which they were published or the authors. The second modality uncovers latent (hidden) patterns of text extracted through hierarchical and semantic non-negative matrix factorization (NMF), such as named entities, topics or clusters, and keywords. We illustrate this concept by consolidating more than two million scientific papers uploaded to arXiv into the cyber-domain, using hierarchical and semantic NMF, and by building a cyber-domain-specific KG. Copyright © 2024, The Authors. All rights reserved.

关键词： Knowledge graph

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Non-equilibrium thermodynamics of charge separation in organic solar cells

arXiv

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arXiv 2019年

作者： Kaiser, W. Janković, V. Vukmirović, N. Gagliardi, A. Department of Electrical and Computer Engineering Technical University of Munich KarlstraÃ e 45 Munich80333 Germany Scientific Computing Laboratory Center for the Study of Complex Systems Institute of Physics Belgrade University of Belgrade Pregrevica 118 Belgrade11080 Serbia

This work presents a novel theoretical description of the non-equilibrium thermodynamics of charge separation process in organic solar cells (OSCs). Using the theory of stochastic thermodynamics, we connect the phonon-assisted dynamics and recombination of electron-hole pairs within a photo-excited organic bilayer with the thermodynamic free energy. We analyze the impact of energetic disorder and delocalization on the free energy, average energy and entropy. For high energetic disorder, the site population is well described by equilibrium. We observe significant deviations from equilibrium for delocalized electron-hole pairs at small energetic disorder, representing efficient OSCs. Our results emphasize that both a large Gibbs entropy and large initial separation are required to achieve efficient charge separation. A decrease in free energy barrier with increased distances between charges does not necessarily correlate with the separation yield. Our presented framework can further shed light on the transient thermodynamic free energy, allowing previously inaccessible insight into the individual thermodynamic contributions from energy and entropy on sub-ns timescales. Transient simulations reveal large Gibbs entropy on ps-timescales for even highest disorder, which may explain the efficient separation of "hot" CT states. Copyright © 2019, The Authors. All rights reserved.

关键词： Organic solar cells

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A 400 MHz, 8-Bit, 1.75-ps Resolution Pipelined-Two-Step Time-to-Digital Converter with Dynamic Time Amplification

A 400 MHz, 8-Bit, 1.75-ps Resolution Pipelined-Two-Step Time...

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IEEE International Symposium on Circuits and systems (ISCAS)

作者： Yuting Tu Rongjin Xu Dawei Ye Liangjian Lyu C.-J. Richard Shi State Key Laboratory of ASIC and System Fudan University Shanghai 201203 China Institute of Brain-inspired Circuits and Systems (iBiCAS) Fudan University Shanghai 201203 China Department of Electrical and Computer Engineering University of Washington Seattle 98195 USA

ISBN: (数字)9781728133201

ISBN: (纸本)9781728133218

This work proposes a high-speed pipelined-two-step time-to-digital converter (TDC) with a dynamic time amplification (DTA) to improve the resolution at low power. The key element of this TDC is the DTA. It samples the residual time errors as voltages held in the MOM capacitors and discharges them to generate the amplified time difference. Thanks to the dynamic time-voltage-time conversion, the DTA realizes high linearity and power efficiency, and can be employed to build a pipeline TDC architecture with high sampling frequency because of its sample and hold operation. Moreover, the DTA maintains constant gain, so only a one-time forground calibration for gain mismatch is required in this TDC. Simulations show that the TDC designed in 65 nm CMOS achieves 8-bit, 1.75 ps of time resolution, and 1 LSB INL and 1.6 LSB DNL with one-time foreground calibration at 400 MHz sampling frequency while just consuming 726 μW power, which corresponds to 18.45 fJ/Conv. FoM.

关键词： Delays Calibration Inverters Capacitors Linearity Tin

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Authenticated key distribution and secure broadcast using no conventional encryption: a unified approach based on block codes

Authenticated key distribution and secure broadcast using no...

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IEEE Conference and Exhibition on Global Telecommunications (GLOBECOM)

作者： R.H. Deng Li Gong A.A. Lazar Weiguo Wang Institute of Systems Science National University of Singapore Singapore Computer Science Laboratory SRI International Inc. Menlo Park CA USA Department of Electrical Engineering and Center for Telecommunications Research Columbia University New York NY USA

To eliminate the use of conventional encryption and to improve protocol efficiency, one-way hash function based authenticated key distribution protocols have appeared in the literature following two distinct approaches: the first approach employs one-way hash function and bit-wise XOR operation; while the second approach makes use of one-way hash function and polynomial interpolation. In this paper, we present a new technique for constructing one-way hash function based protocols for authenticated key distribution. The technique makes use of systematic linear block codes in error-control coding theory, results in more efficient protocols compared with their counterparts in the literature, and in effect, unifies the above two approaches in designing such protocols. As a by product, a secure broadcast protocol is also given which is capable of distributing a data message of any size in one broadcast protocol message.

关键词： Broadcasting Protocols Block codes Polynomials Public key cryptography Authentication computer science Laboratories Data security System performance

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