12,996 research outputs found
Secret Keys Assisted Private Classical Communication Capacity over Quantum Channels
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
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 Lloydâs 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
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
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
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
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-domainâs 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
Review of Online intercultural exchange: Policy, pedagogy, practice
Online intercultural exchange (OIE), also known as telecollaboration, is defined as âthe activity of engaging language learners in interaction and collaborative project work with partners from other cultures through the use of online communication tools such as e-mail, videoconferencing, and discussion forumsâ (OâDowd, 2007, p. 4). Research on OIE has flourished in the past 20 years, evidenced by a large number of journal articles, dedicated journal special issues (e.g., Belz, 2003; Lewis, Chanier, & Youngs, 2011), and edited volumes (Belz & Throne, 2006; Dooly, 2008; Dooly & OâDowd, 2012; Guth & Helm, 2010; OâDowd, 2007; Warschauer, 1995, 1996; Warschauer & Kern, 2000). Compared to other edited volumes on telecollaboration in the market, this book provides a state-of-the-art overview of OIE and focuses on its use in university education around the world. This 17-chapter edited volume consists of five parts: an overview of OIE (Part I), the integration of OIE in university education (Part II), the pedagogy of OIE (Part III), OIE in practice (Part IV), and the future of OIE (Part V)
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