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Security loophole in free-space quantum key distribution due to spatial-mode detector-efficiency mismatch

Physical Review A 2015年第6期91卷 062301-062301页

作者： Shihan Sajeed Poompong Chaiwongkhot Jean-Philippe Bourgoin Thomas Jennewein Norbert Lütkenhaus Vadim Makarov Institute for Quantum Computing University of Waterloo Waterloo Ontario N2L 3G1 Canada Department of Electrical and Computer Engineering University of Waterloo Waterloo Ontario N2L 3G1 Canada Department of Physics and Astronomy University of Waterloo Waterloo Ontario N2L 3G1 Canada Quantum Information Science Program Canadian Institute for Advanced Research Toronto Ontario M5G 1Z8 Canada

In free-space quantum key distribution (QKD), the sensitivity of the receiver's detector channels may depend differently on the spatial mode of incoming photons. Consequently, an attacker can control the spatial mode to break security. We experimentally investigate a standard polarization QKD receiver and identify sources of efficiency mismatch in its optical scheme. We model a practical intercept-and-resend attack and show that it would break security in most situations. We show experimentally that adding an appropriately chosen spatial filter at the receiver's entrance may be an effective countermeasure.

关键词： Quantum cryptography

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Registering sequences of in vivo microscopy images for cell tracking using dynamic programming and minimum spanning trees

Registering sequences of in vivo microscopy images for cell ...

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作者： McArdle, Sara Acton, Scott T. Ley, Klaus Ray, Nilanjan La Jolla Institute for Allergy and Immunology San DiegoCA United States Electrical and Computer Engineering and Biomedical Engineering University of Virginia CharlottesvilleVA United States Department of Computing Science University of Alberta EdmontonAB Canada Department of Bioengineering University of California San Diego San DiegoCA United States

ISBN: (纸本)9781479957514

Registration of in vivo microscopy image sequences is important for tracking of cells. Registering a long sequence of in vivo microscopy images is particularly challenging for several reasons, which include motion artifacts created by the cardiac cycle and breathing movements of the living subject, occasional defocussing, illumination change, and noise in image acquisition. To accommodate these variations, we sample time points redundantly during microscopic image acquisition. Second, we use dynamic programming to select image frames with tolerable motion and eliminate those with large motion. Third, we employ a novel method based on the minimum spanning tree algorithm to register the selected image frames. Testing on actual in vivo image sequences reveals that our approach excels over three existing registration methods in terms of structural image similarity of the registered images. © 2014 IEEE.

关键词： Dynamic programming

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Galvanotactic control of collective cell migration in epithelial monolayers (vol 13, pg 409, 2014)

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NATURE MATERIALS 2014年第5期13卷 530-530页

作者： Cohen, Daniel J. Nelson, W. James Maharbiz, Michel M. Joint Graduate Program in Bioengineering University of California at Berkeley Berkeley California 94720 USA Department of Biology and Molelcular and Cellular Physiology Stanford University Stanford California 94305 USA Department of Electrical Engineering and Computer Science University of California at Berkeley Berkeley California 94720 USA

Many normal and pathological biological processes involve the migration of epithelial cell sheets. This arises from complex emergent behaviour resulting from the interplay between cellular signalling networks and the forces that physically couple the cells. Here, we demonstrate that collective migration of an epithelium can be interactively guided by applying electric fields that bias the underlying signalling networks. We show that complex, spatiotemporal cues are locally interpreted by the epithelium, resulting in rapid, coordinated responses such as a collective U-turn, divergent migration, and unchecked migration against an obstacle. We observed that the degree of external control depends on the size and shape of the cell population, and on the existence of physical coupling between cells. Together, our results offer design and engineering principles for the rational manipulation of the collective behaviour and material properties of a tissue.

关键词： Electric fields

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Size reduction of permanent magnet generators for wind turbines with higher energy density permanent magnets

Size reduction of permanent magnet generators for wind turbi...

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Annual North-American Power Symposium

作者： H. A. Khazdozian R. L. Hadimani D. C. Jiles Wind Energy Science Engineering and Policy Program Department of Electrical & Computer Engineering Iowa State University Ames IA

Permanent magnet generators' (PMGs) dimensions scale with rated power due the sizing law for PMGs, which necessitates increased rotor volume to provide additional torque, preventing use of PMGs in large scale wind turbines. The use of higher energy density permanent magnets may offset the need to scale dimensions to achieve higher input torque. The properties of a permanent magnet necessary to achieve 25% reduction in dimensions in a 10MW wind turbine were calculated. A 29% increase in torque as a result of a 34% increase in the energy product of the permanent magnet is demonstrated.

关键词： Permanent magnets Torque Rotors Magnetic flux Wind turbines Remanence Stators

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Detection of aortic valve dynamics in bridge-to-recovery feedback control of the Left Ventricular Assist Device

Detection of aortic valve dynamics in bridge-to-recovery fee...

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European Control Conference (ECC)

作者： Yu Wang George Faragallah Marwan A. Simaan Department of Bioengineering University of Louisville Louisville KY USA Department of Electrical Engineering and Computer Science University of Central Florida Orlando FL USA

Aortic valve dynamics - which implies continuous opening and closing of the aortic valve in each cardiac cycle during the feedback control of the rotary Left Ventricular Assist Devices (LVAD) support - has important clinical implications for patients with mild congestive heart failure. When the LVAD is implanted in such patients as a bridge-to-recovery device, permanent closure of the aortic valve must be avoided by maintaining proper control on the power delivered to the device. In this paper, a new aortic valve dynamics detection algorithm based on a Lagrangian Support Vector Machine (LSVM) model is presented. A detection indicator is derived from the systemic vascular flow signal in the circulatory system using a nonlinear mathematical model of the combined cardiovascular-LVAD system and forms the input to the LSVM classifier. The LSVM classifier is trained and tested to classify the aortic valve dynamics into two states: aortic valve opening and closing (i.e. operating normally) and aortic valve permanently closed. Our results show that the proposed algorithm can detect the aortic valve dynamics effectively in terms of classification accuracy and stability. This classifier will be an integral part in the development of a feedback controller for the LVAD when used on patients as a bridge-to-recovery device. The output of the classifier will be used to adjust the power delivered to the LVAD to ensure that the aortic valve opens and closes normally within each cardiac cycle while at the same time making sure that the physiological demands of the patient are met.

关键词： Valves Heart Support vector machines Mathematical model Classification algorithms Adaptive control Heuristic algorithms

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Implantable tissue regeneration system using electrical stimulation 18

Implantable tissue regeneration system using electrical stim...

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18th International Conference on Miniaturized Systems for Chemistry and Life sciences, MicroTAS 2014

作者： Kim, Junghoon Cho, Tae Hyung Lee, Sung Eun Yang, Hoon Joo Eom, Kyungsik Kim, In Sook Hwang, Soon Jung Kim, Sung June Department of Electrical Engineering and Computer Science Seoul National University Korea Republic of Dental Research Institute Brain Korea 21 2nd Program for Craniomaxillofacial Life Science Seoul National University Korea Republic of Department of Oral and Maxillofacial Surgery School of Dentistry Brain Korea 21 2nd Program for Craniomaxillofacial Life Science Seoul National University Korea Republic of

ISBN: (纸本)9780979806476

We introduce three implantable tissue regeneration systems;an implantable cell graft culture system, an implantable electrical stimulation system for bone regeneration, and a liquid crystal polymer (LCP)-based bone regeneration device. These devices allow electrical stimulation to stem cell grafts under in vivo circumstances. After a cell culture using the implantable cell graft culture system, we obtained the results of the cell proliferation rate increase of 22% compared with the non-stimulated group. From a bone regeneration experiment using the implantable electrical stimulation system for bone regeneration, the stimulated group showed a higher bone volume by 260% compared with the non-stimulated group. © 14CBMS.

关键词： Stem cells

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Stochastic model checking of genetic circuits

Stochastic model checking of genetic circuits

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作者： Madsen, Curtis Zhang, Zhen Roehner, Nicholas Winstead, Chris Myers, Chris School of Computing Science Newcastle University Newcastle upon Tyne Tyne and WearNE1 7RU United Kingdom Department of Electrical and Computer Engineering University of Utah 201 President Circle Salt Lake CityUT84112 United States Department of Bioengineering University of Utah 201 President Circle Salt Lake CityUT84112 United States Department of Electrical and Computer Engineering Utah State University LogonUT84332 United States

Synthetic genetic circuits have a number of exciting potential applications such as cleaning up toxic waste, hunting and killing tumor cells, and producing drugs and bio-fuels more efficiently. When designing and analyzing genetic circuits, researchers are often interested in the probability of observing certain behaviors. Discerning these probabilities typically involves simulating the circuit to produce some time series data and computing statistics over the resulting data. However, for very rare behaviors of complex genetic circuits, it becomes computationally intractable to obtain good results as the number of required simulation runs grows exponentially. It is, therefore, necessary to apply numerical methods to determine these probabilities directly. This article describes how stochastic model checking, a method for determining the likelihood that certain events occur in a system, can by applied to models of genetic circuits by translating them into continuous-time Markov chains (CTMCs) and analyzing them using Markov chain analysis to check continuous stochastic logic (CSL) properties. The utility of this approach is demonstrated with several case studies illustrating how this method can be used to perform design space exploration of two genetic oscillators and two genetic state-holding elements. Our results show that this method results in a substantial speedup as compared with conventional simulation-based approaches. © 2014 Copyright held by the Owner/Author. Publication rights licensed to ACM.

关键词： Timing circuits

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On determination of LFSR structures to assure more reliable and secure designs of cryptographic systems

On determination of LFSR structures to assure more reliable ...

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International Conference on Reliability, Infocom Technologies and Optimization (ICRITO) (Trends and Future Directions)

作者： Afaq Ahmad Samarth Arora Ahmed Al Maashri Sayyid Samir Al-Busaidi Ali Al Shidhani Electrical and Computer Engineering Sultan Qaboos University Department of Computer Science and Engineering MIT India Under IAESTE program at Sultan Qaboos University Oman

This paper presents an algorithmic procedure for determining the cryptographic key properties and hence matching with the required complexity and strength to assure a more reliable and secure designs of cryptographic systems. The designed algorithm is capable to provide the cryptographic key structure based on optimum solution approach. Using the Hardware Description Language (HDL), Verilog, the key can be realized on Field programmable Gate Array (FPGA) platform and then translated into Printed Circuit Board (PCB).

关键词： computers Ciphers Generators Educational institutions Shift registers Polynomials

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Using energy dispersive spectroscopy (EDS) to determine the resistance of FIB jumpers for circuit edit 40

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40th International Symposium for Testing and Failure Analysis, ISTFA 2014

作者： DiBattista, Michael Senowitz, Corey Faraby, Hasan Bandaru, Prabhakar Qualcomm Incorporated San DiegoCA92121 United States Department of Electrical and Computer Engineering University of California San Diego San DiegoCA92093 United States Department of Mechanical Engineering Materials Science Program University of California San Diego San DiegoCA92093 United States

ISBN: (纸本)1627080740

A key capability of focused ion beam (FIB) tools is the ability to deposit conductive materials by introducing organometallic precursors such as tungsten hexacarbonyl [W(CO)6] or (methylcyclopentadienl) trimethyl platinum [C9H17Pt]. The FIB deposited metal is often used in applications such as the modification of integrated circuits (ICs) by creating new electrical connection on the device. The electrical properties of the FIB material are of particular concern to high speed digital and radio frequency (RF) circuit designers because the resistivity of the FIB deposited metal is orders of magnitude higher in value than the near bulk resistivity value of the metals used in IC manufacturing. In this paper, we developed a correlation between the chemical composition of the FIB deposited metal and the electrical resistivity using an effective media theory (EMT) model. Analysis shows that gallium from the ion beam is the dominant contributor to lowering the resistivity of the jumper. The results of this work and model allow us to understand the role the chemical elements play in the electrical resistance of the FIB electrical jumper and to estimate the FIB metal resistance from energy dispersive spectroscopy (EDS) analysis and the geometry. Copyright © 2014 ASM International® All rights reserved.

关键词： Energy dispersive spectroscopy

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Design and numerical analysis of surface plasmon-enhanced fin Ge-Si light-emitting diode

Design and numerical analysis of surface plasmon-enhanced fi...

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作者： Jeong, Intae Kwon, Jooseong Kim, Changsoon Park, Young June Program in Nano Science and Technology Graduate School of Convergence Science and Technology Seoul National University Seoul 151-742 Korea Republic of Department of Electrical and Computer Engineering School of Engineering Seoul National University Seoul 151-747 Korea Republic of Advanced Institutes of Convergence Technology Suwon Gyeonggi 443-270 Korea Republic of

Heavily-doped strained germanium (Ge) can emit light efficiently thanks to its pseudo direct band gap characteristic. This makes Ge a good candidate for on-chip monolithic light sources in silicon (Si) photonics systems. We propose fin-shaped Ge-Si heterojunction lightemitting diode (LED) with metal gates, which can enhance light emission by coupling with surface plasmon resonant modes and modulate light emission from the LED. We verify these two aspects through numerical analysis and device simulations. We develop the method to find the optimal device structure and specific device dimensions to maximize the spontaneous emission rate enhancement. Also we find that the LED can be modulated by a gate voltage bias. © 2014 Optical Society of America.

关键词： Surface plasmons

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