12,172 research outputs found

    Secret Keys Assisted Private Classical Communication Capacity over Quantum Channels

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    We prove a regularized formula for the secret key-assisted capacity region of a quantum channel for transmitting private classical information. This result parallels the work of Devetak on entanglement assisted quantum communication capacity \cite{DHW05RI}. This formula provides a new family protocol, the private father protocol, under the resource inequality framework that includes private classical communication \it{without} secret key assistance as a child protocol.Comment: 6 pages, 2 figures. Submitted to PR

    Data-driven fault detection using trending analysis

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    The objective of this research is to develop data-driven fault detection methods which do not rely on mathematical models yet are capable of detecting process malfunctions. Instead of using mathematical models for comparing performances, the methods developed rely on extensive collection of data to establish classification schemes that detect faults in new data. The research develops two different trending approaches. One uses the normal data to define a one-class classifier. The second approach uses a data mining technique, e.g. support vector machine (SVM) to define multi class classifiers. Each classifier is trained on a set of example objects. The one-class classification assumes that only information of one of the classes, namely the normal class, is available. The boundary between the two classes, normal and faulty, is estimated from data of the normal class only. The research assumes that the convex hull of the normal data can be used to define a boundary separating normal and faulty data. The multi class classifier is implemented through several binary classifiers. It is assumed that data from two classes are available and the decision boundary is supported from both sides by example objects. In order to detect significant trends in the data the research implements a non-uniform quantization technique, based on Lloyd’s algorithm and defines a special subsequence-based kernel. The effect of the subsequence length is examined through computer simulations and theoretical analysis. The test bed used to collect data and implement the fault detection is a six degrees of freedom, rigid body model of a B747 100/200 and only faults in the actuators are considered. In order to thoroughly test the efficiency of the approach, the test use only sensor data that does not include manipulated variables. Even with this handicap the approach is effective with the average of 79.5% correct detection and 16.7% missed alarm and 3.9% false alarms for six different faults

    Spectral properties of a thresholdless dressed-atom laser

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    We investigate spectral properties of the atomic fluorescence and the output field of the cavity-mode of a single-atom dressed-state laser in a photonic crystal. We pay a particular attention to the behavior of the spectra in the presence of the frequency dependent reservoir and search for signatures of the thresholdless lasing. Although the thresholdless behavior has been predicted by analyzing the photon statistics of the cavity field, we find that the threshold behavior still exists in the spectrum of the cavity field. We find that the structure of cavity field spectrum depends strongly on the strange of the pumping rate. For low pumping rates, the spectrum is not monochromatic, it is composed of a set of discrete lines reveling the discrete (quantum) structure of the combined dressed-atom plus the cavity field system. We find that for a certain value of the pumping rate, the multi-peak structure converts into a single very narrow line centered at the cavity field frequency. A physical explanation of the behavior of the spectra is provided in terms of dressed states of the system.Comment: Special Issue of Journal Modern Optics - Fetschrift in honour of Lorenzo Narducc

    DTER: Schedule Optimal RF Energy Request and Harvest for Internet of Things

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    We propose a new energy harvesting strategy that uses a dedicated energy source (ES) to optimally replenish energy for radio frequency (RF) energy harvesting powered Internet of Things. Specifically, we develop a two-step dual tunnel energy requesting (DTER) strategy that minimizes the energy consumption on both the energy harvesting device and the ES. Besides the causality and capacity constraints that are investigated in the existing approaches, DTER also takes into account the overhead issue and the nonlinear charge characteristics of an energy storage component to make the proposed strategy practical. Both offline and online scenarios are considered in the second step of DTER. To solve the nonlinear optimization problem of the offline scenario, we convert the design of offline optimal energy requesting problem into a classic shortest path problem and thus a global optimal solution can be obtained through dynamic programming (DP) algorithms. The online suboptimal transmission strategy is developed as well. Simulation study verifies that the online strategy can achieve almost the same energy efficiency as the global optimal solution in the long term

    Structural and functional studies of proline catabolic enzymes and human aldehyde dehydrogenases

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    Oxidation of amino acids, like proline catabolism, is a central part of energy metabolism. Proline is oxidized to glutamate by two enzymes: proline dehydrogenase (PRODH) and 1-pyrroline-5-carboxylate dehydrogenase (P5CDH). PRODH catalyzes the first reaction of proline to 1-pyrroline-5-carboxylate (P5C). P5C undergoes a non-enzymatic hydrolysis to glutamate semialdehyde (GSA), which is oxidized to glutamate by a NAD+- dependent enzyme P5CDH. PRODH and P5CDH are mono-functional enzymes in eukaryotes and Gram-positive bacteria; while in Gram-negative bacteria, the two enzymes are fused into one protein as two domains, known as proline utilization A (PutA). This dissertation work involved structural and functional studies of PRODH, P5CDH, PutA, and human aldehyde dehydrogenases (ALDHs). The results illuminated the substrate recognition for mono-functional PRODH and hot spot oligomerization mechanism for mono-functional P5CDH, also, demonstrated that diethylaminobenzaldehyde (DEAB) is a mechanism based inactivator for aldehyde dehydrogenase 7A1. Furthermore, the C-terminal domain found in PutAs, the only domain without any structural and functional information has been structurally and biochemically characterized

    BUILDING A DISTRIBUTED TRUST MODEL OF RESTFUL WEB SERVICES FOR MOBILE DEVICES

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    As of 2011, there were about 5,981 million mobile devices in the world [1] and there are 113.9 million mobile web users in 2012 [2]. With the popularity of web services for mobile devices, the concern of security for mobile devices has been brought up. Furthermore, with more and more cooperation of organizations, web services are now normally involved with more than one organization. How to trust coming requests from other organizations is an issue. This research focuses on building a trust model for the web services of mobile devices. It resolves the issues caused by mobile devices being stolen, lost, users abusing privileges, and cross-domain’s access control. The trust model is distributed in each node of the web servers. The trust value is calculated for every incoming request to decide whether the request should be served or not. The goals of the trust model are 1) flexible; 2) scalable; 3) lightweight. The implementation is designed and accomplished with the goals in mind. The experiments evaluate the overhead for the trust module and maximum capacity of the system
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