WorldWideScience

Sample records for channel state information

  1. Wiretap Channel with Causal State Information

    CERN Document Server

    Chia, Yeow-Khiang

    2010-01-01

    A lower bound on the secrecy capacity of the wiretap channel with state information available causally at both the encoder and decoder is established. The lower bound is shown to be strictly larger than that for the noncausal case by Liu and Chen. Achievability is proved using block Markov coding, Shannon strategy, and key generation from common state information. The state sequence available at the end of each block is used to generate a key, which is used to enhance the transmission rate of the confidential message in the following block. An upper bound on the secrecy capacity when the state is available noncausally at the encoder and decoder is established and is shown to coincide with the lower bound for several classes of wiretap channels with state.

  2. Statistical-mechanical analysis of multiuser channel capacity with imperfect channel state information

    Institute of Scientific and Technical Information of China (English)

    Wang Hui-Song; Zeng Gui-Hua

    2008-01-01

    In this paper,the effect of imperfect channel state information at the receiver, which is caused by noise and other interference, on the multi-access channel capacity is analysed through a statistical-mechanical approach. Replica analyses focus on analytically studying how the minimum mean square error (MMSE) channel estimation error appears in a multiuser channel capacity formula. And the relevant mathematical expressions are derived. At the same time,numerical simulation results are demonstrated to validate the Replica analyses. The simulation results show how the system parameters, such as channel estimation error, system load and signal-to-noise ratio, affect the channel capacity.

  3. On the low SNR capacity of MIMO fading channels with imperfect channel state information

    KAUST Repository

    Benkhelifa, Fatma

    2014-05-01

    The capacity of Multiple Input Multiple Output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low Signal-to-Noise Ratio (SNR) essentially as SNR log(1=SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In our work, we mainly focus on the low SNR regime and we show that the capacity scales as (1-α) SNR log(1=SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can also be extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R. © 2014 IFIP.

  4. On the low SNR capacity of MIMO fading channels with imperfect channel state information

    KAUST Repository

    Benkhelifa, Fatma

    2014-06-01

    The capacity of multiple-input multiple-output (MIMO) Rayleigh fading channels with full knowledge of channel state information (CSI) at both the transmitter and the receiver (CSI-TR) has been shown recently to scale at low signal-to-noise ratio (SNR) essentially as SNR log(1/SNR), independently of the number of transmit and receive antennas. In this paper, we investigate the ergodic capacity of MIMO Rayleigh fading channel with estimated channel state information at the transmitter (CSI-T) and possibly imperfect channel state information at the receiver (CSI-R). Our framework can be seen as a generalization of previous works as it can capture the perfect CSI-TR as a special case when the estimation error variance goes to zero. In this paper, we mainly focus on the low SNR regime, and we show that the capacity scales as (1-α) SNR log(1/SNR), where α is the estimation error variance. This characterization shows the loss of performance due to error estimation over the perfect channel state information at both the transmitter and the receiver. As a by-product of our new analysis, we show that our framework can be also extended to characterize the capacity of MIMO Rician fading channels at low SNR with possibly imperfect CSI-T and CSI-R. © 1972-2012 IEEE.

  5. Ergodic Capacity of Cognitive Radio under Imperfect Channel State Information

    CERN Document Server

    Rezk, Zouheir

    2012-01-01

    A spectrum-sharing communication system where the secondary user is aware of the instantaneous channel state information (CSI) of the secondary link, but knows only the statistics and an estimated version of the secondary transmitter-primary receiver (ST-PR) link, is investigated. The optimum power profile and the ergodic capacity of the secondary link are derived for general fading channels (with continuous probability density function) under average and peak transmit-power constraints and with respect to two different interference constraints: an interference outage constraint and a signal-to-interference outage constraint. When applied to Rayleigh fading channels, our results show, for instance, that the interference constraint is harmful at high-power regime in the sense that the capacity does not increase with the power, whereas at low-power regime, it has a marginal impact and no-interference performance corresponding to the ergodic capacity under average or peak transmit power constraint in absence of ...

  6. Secure Broadcasting with Imperfect Channel State Information at the Transmitter

    KAUST Repository

    Hyadi, Amal

    2015-11-13

    We investigate the problem of secure broadcasting over fast fading channels with imperfect main channel state information (CSI) at the transmitter. In particular, we analyze the effect of the noisy estimation of the main CSI on the throughput of a broadcast channel where the transmission is intended for multiple legitimate receivers in the presence of an eavesdropper. Besides, we consider the realistic case where the transmitter is only aware of the statistics of the eavesdropper’s CSI and not of its channel’s realizations. First, we discuss the common message transmission case where the source broadcasts the same information to all the receivers, and we provide an upper and a lower bounds on the ergodic secrecy capacity. For this case, we show that the secrecy rate is limited by the legitimate receiver having, on average, the worst main channel link and we prove that a non-zero secrecy rate can still be achieved even when the CSI at the transmitter is noisy. Then, we look at the independent messages case where the transmitter broadcasts multiple messages to the receivers, and each intended user is interested in an independent message. For this case, we present an expression for the achievable secrecy sum-rate and an upper bound on the secrecy sum-capacity and we show that, in the limit of large number of legitimate receivers K, our achievable secrecy sum-rate follows the scaling law log((1−) log(K)), where is the estimation error variance of the main CSI. The special cases of high SNR, perfect and no-main CSI are also analyzed. Analytical derivations and numerical results are presented to illustrate the obtained expressions for the case of independent and identically distributed Rayleigh fading channels.

  7. On the capacity of Rician fading channels with full channel state information at low SNR

    KAUST Repository

    Rezki, Zouheir

    2012-06-01

    The capacity of flat Rayleigh fading channels with full channel state information (CSI) at the transmitter and at the receiver at asymptotically low SNR has been recently shown to scale essentially as SNR log (1/SNR). In this paper, we investigate the Rician fading channel capacity with full CSI, and show that the capacity of this channel scales essentially as 1/1+K SNR log (1 /SNR), where K is the Rician factor. This characterization includes perfect CSI at both the transmitter and the receiver or noisy CSI at the transmitter and perfect CSI at the receiver. We also show that one-bit CSI at the transmitter is enough to achieve this asymptotic capacity using an On-Off power control scheme. Our framework may be seen as a generalization of previous works as it captures the Rayleigh fading channel as a special case by letting K goes to zero. © 2012 IEEE.

  8. Multi-Channel Autonomous Information System Performance with Positional Signal State Analyzers at the Channel Outputs

    Directory of Open Access Journals (Sweden)

    V. K. Hohlov

    2016-01-01

    Full Text Available The article presents a statement of technique to research performances of multi-channel combo standalone information systems with positional analyzers of the signal states at the channel outputs. In most cases, in considered multi-channel systems there has been impossible to coincide in time the random moments of signals coming from the objects through various channels in all ways of encounter environment and conditions of practical application. The analyzer makes decision on the signal using the discrete operations on the quantized signals of the certain duration from the channel outputs. The analyzer performance is described by a set of Boolean algebra functions defined for all possible states of the signals at the outputs of the channels, and in the general case is specified in a perfect disjunctive normal form. To determine the validity or falsity of functions of the algebra of logics, which are calculated statements concerning the available or unavailable useful signal at the system input, on the authority of the Poretsky’s theorem and the theory of coincidence in time of the random pulse flow of the channels response because of uncorrelated and correlated noise, are obtained dependences to calculate the probabilities of false alarms and omissions of the signals in discrete combined systems. It is shown that the flows of false alarms because of noise at the channel outputs in the system are Poisson streams. On the basis of the ordinary Poisson flows the paper justifies the relationships for calculating the false alarms of the system with uncorrelated and correlated noise in the channels. The paper also justifies the relationships for performance of multichannel combined systems with positional analyzers of the channels states. Based on the obtained relationships was calculated the average coincidence frequency of the extended pulses of the channel response in a dualchannel system, depending on the noise cross-correlation coefficient with

  9. On the secrecy capacity of the broadcast wiretap channel with imperfect channel state information

    KAUST Repository

    Hyadi, Amal

    2014-12-01

    In this paper, we consider secure broadcasting over fast fading channels. Assuming imperfect main channel state information (CSI) at the transmitter, we first provide an upper and a lower bounds on the ergodic secrecy capacity when a common message is broadcasted to multiple legitimate receivers in the presence of one eavesdropper. For this case, we show that the secrecy rate is limited by the legitimate receiver having, on average, the worst main channel link. Then, we present an expression for the achievable secrecy sum-rate when each legitimate receiver is interested in an independent message. The special cases of high SNR, perfect and no-main CSI are also analyzed. Numerical results are presented to illustrate the obtained results for the case of independent but not necessarily identically distributed Rayleigh fading channels.

  10. On the capacity of multiaccess fading channels with full channel state information at low power regime

    KAUST Repository

    Rezki, Zouheir

    2013-06-01

    We study the throughput capacity region of the Gaussian multiaccess (MAC) fading channel with perfect channel state information (CSI) at the receiver (CSI-R) and at the transmitters (CSI-T), at low power regime. We show that it has a multidimensional rectangle structure and thus is simply characterized by single user capacity points. More specifically, we show that at low power regime, the boundary surface of the capacity region shrinks to a single point corresponding to the sum rate maximizer and that the coordinates of this point coincide with single user capacity bounds. Inspired from this result, we propose an on-off scheme, compute its achievable rate, and provide a necessary condition on the fading channels under which this scheme achieves single user capacity bounds of the MAC channel at asymptotically low power regime. We argue that this necessary condition characterizes a class of fading that encompasses all known wireless channels, where the capacity region of the MAC channel has a simple expression in terms of users\\' average power constraints only. © 2013 IEEE.

  11. On the capacity of cognitive radio under limited channel state information over fading channels

    KAUST Repository

    Rezki, Zouheir

    2011-06-01

    A spectrum-sharing communication system where the secondary user is aware of the instantaneous channel state information (CSI) of the secondary link, but knows only the statistics and an estimated version of the secondary transmitter-primary receiver (ST-PR) link, is investigated. The optimum power profile and the ergodic capacity of the secondary link are derived for general fading channels (with continuous probability density function) under average and peak transmit-power constraints and with respect to two different interference constraints: an interference outage constraint and a signal-to-interference (SI) outage constraint. When applied to Rayleigh fading channels, our results show, for instance, that the interference constraint is harmful at high-power regime, whereas at low-power regime, it has a marginal impact and no-interference performance may be achieved. © 2011 IEEE.

  12. MIMO Relaying Broadcast Channels with Linear Precoding and Quantized Channel State Information Feedback

    CERN Document Server

    Xu, Wei; Lu, Wu-Sheng; 10.1109/TSP.2010.2056687

    2012-01-01

    Multi-antenna relaying has emerged as a promising technology to enhance the system performance in cellular networks. However, when precoding techniques are utilized to obtain multi-antenna gains, the system generally requires channel state information (CSI) at the transmitters. We consider a linear precoding scheme in a MIMO relaying broadcast channel with quantized CSI feedback from both two-hop links. With this scheme, each remote user feeds back its quantized CSI to the relay, and the relay sends back the quantized precoding information to the base station (BS). An upper bound on the rate loss due to quantized channel knowledge is first characterized. Then, in order to maintain the rate loss within a predetermined gap for growing SNRs, a strategy of scaling quantization quality of both two-hop links is proposed. It is revealed that the numbers of feedback bits of both links should scale linearly with the transmit power at the relay, while only the bit number of feedback from the relay to the BS needs to gr...

  13. Information-guided communications in MIMO systems with channel state impairments

    KAUST Repository

    Yang, Yuli

    2013-06-20

    Information-guided channel hopping (IGCH) is a promising technique for high-data-rate communications using multiple antennas for information mapping at the transmitter and optional antenna diversity at the receiver. Compared with some popular multi-antenna techniques, the advantage of this scheme is proven in ideal channel conditions, where the channel is spatially white and the perfect channel state information is assumed available at the receiver. The main objective of this paper is to present an information theoretical study on IGCH in realistic propagation environments with channel degeneracy due to spatial correlation and keyhole phenomena as well as imperfect channel estimation. It is proven that good performance promised by IGCH can be achieved in a variety of non-ideal channel conditions. Moreover, the analysis in this paper provides a convenient tool for the corresponding system design in practical operating environments. © 2013 John Wiley & Sons, Ltd.

  14. Channel Capacity Bounds in the Presence of Quantized Channel State Information

    Directory of Open Access Journals (Sweden)

    Makki Behrooz

    2010-01-01

    Full Text Available The goal of this paper is to investigate the effect of channel side information on increasing the achievable rates of continuous power-limited non-Gaussian channels. We focus on the case where (1 there is imperfect channel quality information available to the transmitter and the receiver and (2 while the channel gain is continuously varying, there are few cross-region changes, and the noise characteristics remain in each detection region for a long time. The results are presented for two scenarios, namely, reliable and unreliable region detection. Considering short- and long-term power constraints, the capacity bounds are found for log-normal and two different Nakagami-based channel distributions, and for both Max-Lloyd and equal probability quantization approaches. Then, the optimal gain partitioning approach, maximizing the achievable rates, is determined. Finally, general equations for the channel capacity bounds and optimal channel partitioning in the case of unreliable region detection are presented. Interestingly, the results show that, for high SNR's, it is possible to determine a power-independent optimal gain partitioning approach maximizing the capacity lower bound which, in both scenarios, is identical for both short- and long-term power constraints.

  15. On the capacity of nakagami-m fading Channels with full channel state information at low SNR

    KAUST Repository

    Rezki, Zouheir

    2012-06-01

    The capacity of flat Rayleigh fading channels with full channel state information (CSI) at the transmitter and at the receiver at asymptotically low SNR has been recently shown to scale essentially as SNR log(1/SNR)}. In this paper, we investigate the Nakagami-m fading channel capacity with full CSI, and show that the capacity of this channel scales essentially as m/ Omega SNR log(1/SNR), where m is the Nakagami-m fading parameter and where Ω is the channel mean-square. We also show that one-bit CSI at the transmitter is enough to achieve this asymptotic capacity using an On-Off power control scheme. Our framework may be seen as a generalization of previous works as it captures the Rayleigh fading channel as a special case by taking m=1. © 2012 IEEE.

  16. On the capacity of multiple access and broadcast fading channels with full channel state information at low SNR

    KAUST Repository

    Rezki, Zouheir

    2014-01-01

    We study the throughput capacity region of the Gaussian multi-access (MAC) fading channel with perfect channel state information (CSI) at the receiver and at the transmitters, at low power regime. We show that it has a multidimensional rectangle structure and thus is simply characterized by single user capacity points.More specifically, we show that at low power regime, the boundary surface of the capacity region shrinks to a single point corresponding to the sum rate maximizer and that the coordinates of this point coincide with single user capacity bounds. Inspired from this result, we propose an on-off scheme, compute its achievable rate, and show that this scheme achieves single user capacity bounds of the MAC channel for a wide class of fading channels at asymptotically low power regime. We argue that this class of fading encompasses all known wireless channels for which the capacity region of the MAC channel has even a simpler expression in terms of users\\' average power constraints only. Using the duality of Gaussian MAC and broadcast channels (BC), we deduce a simple characterization of the BC capacity region at low power regime and show that for a class of fading channels (including Rayleigh fading), time-sharing is asymptotically optimal. © 2014 IEEE.

  17. On the low SNR capacity of maximum ratio combining over rician fading channels with full channel state information

    KAUST Repository

    Benkhelifa, Fatma

    2013-04-01

    In this letter, we study the ergodic capacity of a maximum ratio combining (MRC) Rician fading channel with full channel state information (CSI) at the transmitter and at the receiver. We focus on the low Signal-to-Noise Ratio (SNR) regime and we show that the capacity scales as L ΩK+L SNRx log(1SNR), where Ω is the expected channel gain per branch, K is the Rician fading factor, and L is the number of diversity branches. We show that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-off power control scheme. Our framework can be seen as a generalization of recently established results regarding the fading-channels capacity characterization in the low-SNR regime. © 2012 IEEE.

  18. Generalized HARQ Protocols with Delayed Channel State Information and Average Latency Constraints

    DEFF Research Database (Denmark)

    Trillingsgaard, Kasper Fløe; Popovski, Petar

    2017-01-01

    In many practical wireless systems, the signal-to-interference-and-noise ratio (SINR) that is applicable to a certain transmission, referred to as channel state information (CSI), can only be learned after the transmission has taken place and is thereby delayed (outdated). In such systems, hybrid...

  19. On the capacity of multiple access and broadcast fading Channels with full channel state information at low power regime

    KAUST Repository

    Rezki, Zouheir

    2013-07-01

    We study the throughput capacity region of the Gaussian multi-access (MAC) fading channel with perfect channel state information (CSI) at the receiver and at the transmitters (CSI-TR), at low power regime. We show that it has a multidimensional rectangle structure and thus is simply characterized by single user capacity points. More specifically, we show that at low power regime, the boundary surface of the capacity region shrinks to a single point corresponding to the sum-rate maximizer and that the coordinates of this point coincide with single user capacity bounds. Using the duality of Gaussian MAC and broadcast channels (BC), we provide a simple characterization of the BC capacity region at low power regime. © 2013 IEEE.

  20. On the capacity of cognitive radio under limited channel state information

    KAUST Repository

    Rezki, Zouheir

    2010-09-01

    A spectrum-sharing communication system where the secondary user is aware of the instantaneous channel state information (CSI) of the secondary link, but knows only the statistics of the secondary transmitter-primary receiver link, is investigated. The optimum power profile and the ergodic capacity of the secondary link are derived for general fading channels (with continuous probability density function) under average and peak transmit-power constraints and with respect to two different interference constraints: an interference outage constraint and a signal-to-interference (SI) outage constraint. When applied to Rayleigh fading channels, our results show that the interference constraint is harmful at high-power regime, whereas at lowpower regime, it has a marginal impact and no-interference performance may be achieved. © 2010 IEEE.

  1. Performance limits of energy harvesting communications under imperfect channel state information

    KAUST Repository

    Zenaidi, Mohamed Ridha

    2016-07-26

    In energy harvesting communications, the transmitters have to adapt transmission to availability of energy harvested during the course of communication. The performance of the transmission depends on the channel conditions which vary randomly due to mobility and environmental changes. In this paper, we consider the problem of power allocation taking into account the energy arrivals over time and the degree of channel state information (CSI) available at the transmitter, in order to maximize the throughput. Differently from previous work, the CSI at the transmitter is not perfect and may include estimation errors. We solve this problem with respect to the causality and energy storage constraints. We determine the optimal offline policy in the case where the channel is assumed to be perfectly known at the receiver. Also, we obtain the power policy when the transmitter has no CSI. Furthermore, we analyze the asymptotic average throughput in a system where the average recharge rate goes asymptotically to zero. © 2016 IEEE.

  2. Uplink transmit beamforming design for SINR maximization with full multiuser channel state information

    Science.gov (United States)

    Xi, Songnan; Zoltowski, Michael D.

    2008-04-01

    Multiuser multiple-input multiple-output (MIMO) systems are considered in this paper. We continue our research on uplink transmit beamforming design for multiple users under the assumption that the full multiuser channel state information, which is the collection of the channel state information between each of the users and the base station, is known not only to the receiver but also to all the transmitters. We propose an algorithm for designing optimal beamforming weights in terms of maximizing the signal-to-interference-plus-noise ratio (SINR). Through statistical modeling, we decouple the original mathematically intractable optimization problem and achieved a closed-form solution. As in our previous work, the minimum mean-squared error (MMSE) receiver with successive interference cancellation (SIC) is adopted for multiuser detection. The proposed scheme is compared with an existing jointly optimized transceiver design, referred to as the joint transceiver in this paper, and our previously proposed eigen-beamforming algorithm. Simulation results demonstrate that our algorithm, with much less computational burden, accomplishes almost the same performance as the joint transceiver for spatially independent MIMO channel and even better performance for spatially correlated MIMO channels. And it always works better than our previously proposed eigen beamforming algorithm.

  3. Capacity of cognitive radio under imperfect secondary and cross link channel state information

    KAUST Repository

    Sboui, Lokman

    2011-09-01

    In this paper, we study the ergodic capacity of secondary user channel in a spectrum sharing scenario in which the secondary transmitter is instantaneously aware of estimated versions of the cross link (between the secondary transmitter and the primary receiver) and the secondary link Channel State Information (CSI). The secondary link optimal power profile along with the ergodic capacity are derived for a class of fading channels, under an average power constraint and an instantaneous interference outage constraint. We also show that our framework is rather general as it encompasses several previously studied spectrum sharing settings as special cases. In order to gain some insights on the capacity behavior, numerical results are shown for independent Rayleigh fading channels where it is found for instance, that at low SNR regime, only the secondary channel estimation matters and that the cross link CSI has no effect on the ergodic capacity; whereas at high SNR regime, the capacity is rather driven by the cross link CSI. © 2011 IEEE.

  4. Effective capacity of Nakagami-m fading channels with full channel state information in the low power regime

    KAUST Repository

    Benkhelifa, Fatma

    2013-09-01

    The effective capacity have been introduced by Wu and Neji as a link-layer model supporting statistical delay QoS requirements. In this paper, we propose to study the effective capacity of a Nakagami-m fading channel with full channel state information (CSI) at both the transmitter and at the receiver. We focus on the low Signal-to-Noise Ratio (SNR) regime. We show that the effective capacity for any arbitrary but finite statistically delay Quality of Service (QoS) exponent θ, scales essentially as S NRlog(1/SNR) exactly as the ergodic capacity, independently of any QoS constraint. We also characterize the minimum energy required for reliable communication, and the wideband slope to show that our results are in agreement with results established recently by Gursoy et al. We also propose an on-off power control scheme that achieves the capacity asymptotically using only one bit CSI feedback at the transmitter. Finally, some numerical results are presented to show the accuracy of our asymptotic results. © 2013 IEEE.

  5. Ergodic Capacity of Cognitive Radio Under Imperfect Channel-State Information

    KAUST Repository

    Rezki, Zouheir

    2012-09-08

    A spectrum-sharing communication system where the secondary user is aware of the instantaneous channel-state information (CSI) of the secondary link but knows only the statistics and an estimated version of the secondary transmitter-primary receiver link is investigated. The optimum power profile and the ergodic capacity of the secondary link are derived for general fading channels [with a continuous probability density function (pdf)] under the average and peak transmit power constraints and with respect to the following two different interference constraints: 1) an interference outage constraint and 2) a signal-to-interference outage constraint. When applied to Rayleigh fading channels, our results show, for example, that the interference constraint is harmful at the high-power regime, because the capacity does not increase with the power, whereas at the low-power regime, it has a marginal impact and no-interference performance, which corresponds to the ergodic capacity under average or peak transmit power constraint in the absence of the primary user, may be achieved. © 2012 IEEE.

  6. Performance Limits of Online Energy Harvesting Communications with Noisy Channel State Information at the Transmitter

    KAUST Repository

    Zenaidi, Mohamed Ridha

    2017-03-01

    In energy harvesting communications, the transceivers have to adjust the data transmission to the energy scavenged during the course of communication. The performance of the transmission depends on the channel conditions which vary randomly due to mobility and environmental changes. In this paper, we consider the problem of power allocation taking into account the energy arrivals over time and the quality of channel state information (CSI) measured at the transmitter, in order to maximize the throughput. Differently from previous work, we focus on energy harvesting communications where the CSI at the transmitter is not perfect and may include estimation errors. In the present paper, we introduce a Markov process that models the energy arrival process. Indeed, we solve the throughput maximization problem with respect to energy harvesting constraints. We show that the optimal online power policy can be found using dynamic programming. Furthermore, we study the asymptotic behavior of the communication system at low and high average recharge rate (ARR) regime. Selected numerical results are provided to support our analysis.

  7. Non-cooperative Feedback Rate Control Game for Channel State Information in Wireless Networks

    CERN Document Server

    Song, Lingyang; Zhang, Zhongshan; Jiao, Bingli

    2011-01-01

    It has been well recognized that channel state information (CSI) feedback is of great importance for dowlink transmissions of closed-loop wireless networks. However, the existing work typically researched the CSI feedback problem for each individual mobile station (MS), and thus, cannot efficiently model the interactions among self-interested mobile users in the network level. To this end, in this paper, we propose an alternative approach to investigate the CSI feedback rate control problem in the analytical setting of a game theoretic framework, in which a multiple-antenna base station (BS) communicates with a number of co-channel MSs through linear precoder. Specifically, we first present a non-cooperative feedback-rate control game (NFC), in which each MS selects the feedback rate to maximize its performance in a distributed way. To improve efficiency from a social optimum point of view, we then introduce pricing, called the non-cooperative feedback-rate control game with price (NFCP). The game utility is ...

  8. Relay selection based on MAP estimation for cooperative communication with outdated channel state information

    Institute of Scientific and Technical Information of China (English)

    Ding Wenrui; Fei Li; Gao Qiang; Liu Shuo

    2013-01-01

    In this paper,we consider an amplify-and-forward (AF) cooperative communication system when the channel state information (CSI) used in relay selection differs from that during data transmission,i.e.,the CSI used in relay selection is outdated.The selected relay may not be actually the best for data transmission and the outage performance of the cooperative system will deteriorate.To improve its performance,we propose a relay selection strategy based on maximum a posteriori (MAP) estimation,where relay is selected based on predicted signal-to-noise ratio (SNR).To reduce the computation complexity,we approximate the a posteriori probability density of SNR and obtain a closed-form predicted SNR,and a relay selection strategy based on the approximate MAP estimation (RS-AMAP) is proposed.The simulation results show that this approximation leads to trivial performance loss from the perspective of outage probability.Compared with relay selection strategies given in the literature,the outage probability is reduced largely through RS-AMAP for medium-to-large transmitting powers and medium-to-high channel correlation coefficients.

  9. Adaptive rate transmission for spectrum sharing system with quantized channel state information

    KAUST Repository

    Abdallah, Mohamed M.

    2011-03-01

    The capacity of a secondary link in spectrum sharing systems has been recently investigated in fading environments. In particular, the secondary transmitter is allowed to adapt its power and rate to maximize its capacity subject to the constraint of maximum interference level allowed at the primary receiver. In most of the literature, it was assumed that estimates of the channel state information (CSI) of the secondary link and the interference level are made available at the secondary transmitter via an infinite-resolution feedback links between the secondary/primary receivers and the secondary transmitter. However, the assumption of having infinite resolution feedback links is not always practical as it requires an excessive amount of bandwidth. In this paper we develop a framework for optimizing the performance of the secondary link in terms of the average spectral efficiency assuming quantized CSI available at the secondary transmitter. We develop a computationally efficient algorithm for optimally quantizing the CSI and finding the optimal power and rate employed at the cognitive transmitter for each quantized CSI level so as to maximize the average spectral efficiency. Our results give the number of bits required to represent the CSI sufficient to achieve almost the maximum average spectral efficiency attained using full knowledge of the CSI for Rayleigh fading channels. © 2011 IEEE.

  10. Energy efficiency for cloud-radio access networks with imperfect channel state information

    KAUST Repository

    Al-Oquibi, Bayan

    2016-12-24

    The advent of smartphones and tablets over the past several years has resulted in a drastic increase of global carbon footprint, due to the explosive growth of data traffic. Improving energy efficiency (EE) becomes, therefore, a crucial design metric in next generation wireless systems (5G). Cloud radio access network (C-RAN), a promising 5G network architecture, provides an efficient framework for improving the EE performance, by means of coordinating the transmission across the network. This paper considers a C-RAN system formed by several clusters of remote radio heads (RRHs), each serving a predetermined set of mobile users (MUs), and assumes imperfect channel state information (CSI). The network performance becomes therefore a function of the intra-cluster and inter-cluster interference, as well as the channel estimation error. The paper optimizes the transmit power of each RRH in order to maximize the network global EE subject to MU service rate requirements and RRHs maximum power constraints. The paper proposes solving the optimization problem using a heuristic algorithm based on techniques from optimization theory via a two-stage iterative solution. Simulation results show that the proposed power allocation algorithm provides an appreciable performance improvement as compared to the conventional systems with maximum power transmission strategy. They further highlight the convergence of the proposed algorithm for different networks scenarios.

  11. Cooperative Transmission for Relay Networks Based on Second-Order Statistics of Channel State Information

    Science.gov (United States)

    Li, Jiangyuan; Petropulu, Athina P.; Poor, H. Vincent

    2011-03-01

    Cooperative beamforming in relay networks is considered, in which a source transmits to its destination with the help of a set of cooperating nodes. The source first transmits locally. The cooperating nodes that receive the source signal retransmit a weighted version of it in an amplify-and-forward (AF) fashion. Assuming knowledge of the second-order statistics of the channel state information, beamforming weights are determined so that the signal-to-noise ratio (SNR) at the destination is maximized subject to two different power constraints, i.e., a total (source and relay) power constraint, and individual relay power constraints. For the former constraint, the original problem is transformed into a problem of one variable, which can be solved via Newton's method. For the latter constraint, the original problem is transformed into a homogeneous quadratically constrained quadratic programming (QCQP) problem. In this case, it is shown that when the number of relays does not exceed three the global solution can always be constructed via semidefinite programming (SDP) relaxation and the matrix rank-one decomposition technique. For the cases in which the SDP relaxation does not generate a rank one solution, two methods are proposed to solve the problem: the first one is based on the coordinate descent method, and the second one transforms the QCQP problem into an infinity norm maximization problem in which a smooth finite norm approximation can lead to the solution using the augmented Lagrangian method.

  12. Information geometry of Gaussian channels

    CERN Document Server

    Monras, Alex

    2009-01-01

    We define a local Riemannian metric tensor in the manifold of Gaussian channels and the distance that it induces. We adopt an information-geometric approach and define a metric derived from the Bures-Fisher metric for quantum states. The resulting metric inherits several desirable properties from the Bures-Fisher metric and is operationally motivated from distinguishability considerations: It serves as an upper bound to the attainable quantum Fisher information for the channel parameters using Gaussian states, under some restriction on the available resources. We prove that optimal states are always pure and bounded in the number of ancillary modes that are needed. This has experimental and computational advantages: It limits the complexity of optimal experimental setups for channel estimation and reduces the computational requirements for the evaluation of the metric. Indeed, we construct a converging algorithm for computing the metric. We provide explicit formulae for computing the multiparametric quantum F...

  13. A CROSS-LAYER SCHEDULER WITH CHANNEL STATE INFORMATION FOR GUARANTEED QUALITY OF SERVICE

    Directory of Open Access Journals (Sweden)

    R. Nandhini

    2014-01-01

    Full Text Available WiMAX networks are deployed for commercial use because of its nature high bandwidth. This requirement invokes the application level changes in QoS provisioning techniques. The objective of the broadband wireless technologies is to ensure the end to end Quality of Service (QoS for the service classes. WiMAX is a revolution in wireless networks, which could support real time multimedia services. In order to provide QoS support and efficient usage of system resources an intelligent scheduling algorithm is needed. The design of the detailed scheduling algorithm is a major focus for researchers and service providers. In this study, a channel aware cross-layer scheduling algorithm for WiMAX networks has been proposed. This scheme employs the Signal to Noise Ratio (SNR value, which allocates the bandwidth based on the information about the quality of the channel and the service requirements of each connection. The proposed algorithm is described in detail and evaluated, through a series of simulations. The QoS parameters of throughput, bandwidth efficiency and transmission efficiency have been measured in simulation.

  14. Joint Linear Processing for an Amplify-and-Forward MIMO Relay Channel with Imperfect Channel State Information

    Directory of Open Access Journals (Sweden)

    Vandendorpe Luc

    2010-01-01

    Full Text Available The problem of jointly optimizing the source precoder, relay transceiver, and destination equalizer has been considered in this paper for a multiple-input-multiple-output (MIMO amplify-and-forward (AF relay channel, where the channel estimates of all links are assumed to be imperfect. The considered joint optimization problem is nonconvex and does not offer closed-form solutions. However, it has been shown that the optimization of one variable when others are fixed is a convex optimization problem which can be efficiently solved using interior-point algorithms. In this context, an iterative technique with the guaranteed convergence has been proposed for the AF MIMO relay channel that includes the direct link. It has been also shown that, for the double-hop relay case without the receive-side antenna correlations in each hop, the global optimality can be confirmed since the structures of the source precoder, relay transceiver, and destination equalizer have closed forms and the remaining joint power allocation can be solved using Geometric Programming (GP technique under high signal-to-noise ratio (SNR approximation. In the latter case, the performance of the iterative technique and the GP method has been compared with simulations to ensure that the iterative approach gives reasonably good solutions with an acceptable complexity. Moreover, simulation results verify the robustness of the proposed design when compared to the nonrobust design that assumes estimated channels as actual channels.

  15. Joint Linear Processing for an Amplify-and-Forward MIMO Relay Channel with Imperfect Channel State Information

    Science.gov (United States)

    Chalise, Batu K.; Vandendorpe, Luc

    2010-12-01

    The problem of jointly optimizing the source precoder, relay transceiver, and destination equalizer has been considered in this paper for a multiple-input-multiple-output (MIMO) amplify-and-forward (AF) relay channel, where the channel estimates of all links are assumed to be imperfect. The considered joint optimization problem is nonconvex and does not offer closed-form solutions. However, it has been shown that the optimization of one variable when others are fixed is a convex optimization problem which can be efficiently solved using interior-point algorithms. In this context, an iterative technique with the guaranteed convergence has been proposed for the AF MIMO relay channel that includes the direct link. It has been also shown that, for the double-hop relay case without the receive-side antenna correlations in each hop, the global optimality can be confirmed since the structures of the source precoder, relay transceiver, and destination equalizer have closed forms and the remaining joint power allocation can be solved using Geometric Programming (GP) technique under high signal-to-noise ratio (SNR) approximation. In the latter case, the performance of the iterative technique and the GP method has been compared with simulations to ensure that the iterative approach gives reasonably good solutions with an acceptable complexity. Moreover, simulation results verify the robustness of the proposed design when compared to the nonrobust design that assumes estimated channels as actual channels.

  16. Optimal Use of Current and Outdated Channel State Information - Degrees of Freedom of the MISO BC with Mixed CSIT

    CERN Document Server

    Gou, Tiangao

    2012-01-01

    We consider a multiple-input-single-output (MISO) broadcast channel with mixed channel state information at the transmitter (CSIT) that consists of imperfect current CSIT and perfect outdated CSIT. Recent work by Kobayashi et al. presented a scheme which exploits both imperfect current CSIT and perfect outdated CSIT and achieves higher degrees of freedom (DoF) than possible with only imperfect current CSIT or only outdated CSIT individually. In this work, we further improve the achievable DoF in this setting by incorporating additional private messages, and provide a tight information theoretic DoF outer bound, thereby identifying the DoF optimal use of mixed CSIT. The new result is stronger even in the original setting of only delayed CSIT, because it allows us to remove the restricting assumption of statistically equivalent fading for all users.

  17. Information transfer through quantum channels

    Energy Technology Data Exchange (ETDEWEB)

    Kretschmann, D.

    2007-03-12

    channel. We then explain how all known coding theorems can be generalized from memoryless channels to forgetful memory channels. We also present examples for non-forgetful channels, and derive generic entropic upper bounds on their capacities for (private) classical and quantum information transfer. Ch. 7 provides a brief introduction to quantum information spectrum methods as a promising approach to coding theorems for completely general quantum sources and channels. We present a data compression theorem for general quantum sources and apply these results to ergodic as well as mixed sources. Finally we investigate the continuity of distillable entanglement - another key notion of the field, which characterizes the optimal asymptotic rate at which maximally entangled states can be generated from many copies of a less entangled state. We derive uniform norm bounds for all states with full support, and we extend some of these results to quantum channel capacities. (orig.)

  18. SVD-Aided Power Allocation and Iterative Detection Scheme for Turbo-BLAST System with Imperfect Channel State Information

    Directory of Open Access Journals (Sweden)

    Xiaomin Chen

    2011-01-01

    Full Text Available A new technique that combines adaptive power allocation and iterative detection based on singular value decomposition (SVD is introduced for the modified Turbo-BLAST system with imperfect channel state information (I-CSI. At the transmitter, in order to maximize the capacity performance, the MIMO channel is decomposed into several parallel eigen subchannels by SVD, and then proper power based on the water-filling principle is allocated to every subchannel subject to the total transmit power constraint. At the receiver, the modified MMSE detector taking the CSI imperfection into account is used to remove the coantenna interference, and then the turbo idea is employed for iterative detection to lower the system BER. As a result, the BER performance is effectively enhanced. Numerical results show that the introduced SVD-aided adaptive power allocation method is valid to improve not only the capacity but also the BER performance in the presence of channel state information imperfection, while the iterative detector can further lower the BER results.

  19. Performance of Pre-processing Schemes with Imperfect Channel State Information

    DEFF Research Database (Denmark)

    Christensen, Søren Skovgaard; Kyritsi, Persa; De Carvalho, Elisabeth

    2006-01-01

    Pre-processing techniques have several benefits when the CSI is perfect. In this work we investigate three linear pre-processing filters, assuming imperfect CSI caused by noise degradation and channel temporal variation. Results indicate, that the LMMSE filter achieves the lowest BER and the high...... and the highest SINR when the CSI is perfect, whereas the simple matched filter may be a good choice when the CSI is imperfect. Additionally the results give insight into the inherent trade-off between robustness against CSI imperfections and spatial focusing ability....

  20. Outage performance of opportunistic two-way amplify-and-forward relaying with outdated channel state information

    KAUST Repository

    Hwang, Kyusung

    2013-09-01

    In this paper, we study the outage performance of an amplify-and-forward (AF)-based two-way relaying (TWR) system with multiple relays where a single relay selection is performed based on outdated channel state information (CSI). Specifically, we propose a single relay selection scheme in AF-based TWR system under outdated CSI conditions. With this policy, we offer a statistical analysis of the signal-to-noise ratio per hop and analyze the outage probability with asymmetric outage thresholds based on CSI-assisted AF protocol. Additionally, we provide the exact and asymptotic expressions based on the provided statistical/joint statistical analyses of a dual-hop AF transmission. Finally, we verify our analytical results with some selected computer-based simulation results. © 1972-2012 IEEE.

  1. Energy-Efficient Power Allocation for Fixed-Gain Amplify-and-Forward Relay Networks with Partial Channel State Information

    KAUST Repository

    Zafar, Ammar

    2012-06-01

    In this report, energy-efficient transmission and power allocation for fixed-gain amplify-and-forward relay networks with partial channel state information (CSI) are studied. In the energy-efficiency problem, the total power consumed is minimized while keeping the signal-to-noise-ratio (SNR) above a certain threshold. In the dual problem of power allocation, the end-to-end SNR is maximized under individual and global power constraints. Closed-form expressions for the optimal source and relay powers and the Lagrangian multiplier are obtained. Numerical results show that the optimal power allocation with partial CSI provides comparable performance as optimal power allocation with full CSI at low SNR.

  2. Energy-Efficient Power Allocation for Fixed-Gain Amplify-and-Forward Relay Networks with Partial Channel State Information

    KAUST Repository

    Zafar, Ammar

    2012-09-16

    In this letter, energy-efficient transmission and power allocation for fixed-gain amplify-and-forward relay networks with partial channel state information (CSI) are studied. In the energy-efficiency problem, the total power consumed is minimized while keeping the signal-to-noise-ratio (SNR) above a certain threshold. In the dual problem of power allocation, the end-to-end SNR is maximized under individual and global power constraints. Closed-form expressions for the optimal source and relay powers and the Lagrangian multiplier are obtained. Numerical results show that the optimal power allocation with partial CSI provides comparable performance as optimal power allocation with full CSI at low SNR. © 2012 IEEE.

  3. Information capacities of quantum measurement channels

    Science.gov (United States)

    Holevo, A. S.

    2013-03-01

    We study the relation between the unassisted and entanglement-assisted classical capacities C and Cea of entanglement-breaking channels. We argue that the gain of entanglement assistance Cea/C > 1 generically for measurement channels with unsharp observables; in particular for the measurements with pure posterior states the information loss in the entanglement-assisted protocol is zero, resulting in an arbitrarily large gain for very noisy or weak signal channels. This is illustrated by examples of continuous observables corresponding to state tomography in finite dimensions and heterodyne measurement. In contrast, state preparations are characterized by the property of having no gain of entanglement assistance, Cea/C = 1.

  4. Mutual Information of Pauli Channels with Correlated Noise

    Institute of Scientific and Technical Information of China (English)

    HOU Li-zhen; FANG Mao-Fa

    2007-01-01

    A general formula for the mutual information of the Pauli channels with memory modelled by correlated noise is derived.It is shown that the mutual information depends on the channel shrinking factor,the input state parameter and the channel memory coefficient.The analyses based on the general formula reveal that the entanglement is always a useful resource to enhance the mutual information of some.Pauli channels,such as the bit flip channel and the bit-phase flip channel.Our analyses also show that the entanglement is not advantageous to the reliable transmission of classical information for Borne Pauli channels at any time,such as the phase flip channel and the phase damping channel.

  5. Dynamical Equations for Quantum Information and Application in Information Channel

    Institute of Scientific and Technical Information of China (English)

    BI Qiao; XING Xiu-San; H. E. Ruda

    2005-01-01

    @@ We establish several dynamical equations for quantum information density. It is demonstrated that quantum information density shares the same formalism of the Liouville equation, subdynamics kinetic equation and Fokker-Planck equation as the density operator and also possesses the superposition property. These allow one to use quantum information density directly to model quantum information. The kinetic equations for quantum information density reveal that the dynamical process of quantum information may be related to dissipative,Markovian, or diffusional information flows, together causing irreversibility. Finally, we discuss superposition of quantum information density, which allows us to construct a quantum information channel in the coherent state representation using harmonic oscillator based encoded quantum information, and obtain a formula for quantum dynamical mutual information.

  6. Covert channel detection using Information Theory

    CERN Document Server

    Hélouët, Loïc; 10.4204/EPTCS.51.3

    2011-01-01

    This paper presents an information theory based detection framework for covert channels. We first show that the usual notion of interference does not characterize the notion of deliberate information flow of covert channels. We then show that even an enhanced notion of "iterated multivalued interference" can not capture flows with capacity lower than one bit of information per channel use. We then characterize and compute the capacity of covert channels that use control flows for a class of systems.

  7. Covert channel detection using Information Theory

    Directory of Open Access Journals (Sweden)

    Loïc Hélouët

    2011-02-01

    Full Text Available This paper presents an information theory based detection framework for covert channels. We first show that the usual notion of interference does not characterize the notion of deliberate information flow of covert channels. We then show that even an enhanced notion of "iterated multivalued interference" can not capture flows with capacity lower than one bit of information per channel use. We then characterize and compute the capacity of covert channels that use control flows for a class of systems.

  8. Interference Alignment with Analog Channel State Feedback

    CERN Document Server

    Ayach, Omar El

    2010-01-01

    Interference alignment (IA) is a multiplexing gain optimal transmission strategy for the interference channel with an arbitrary number of users. While the achieved sum rate with IA is much higher than previously thought possible, the improvement comes at the cost of requiring network channel state information at the transmitters. This can be achieved by explicit feedback, a flexible yet costly approach that incurs large overhead and limits throughput. We propose using analog feedback as an alternative to limited feedback or reciprocity based alignment. We show that the full multiplexing gain observed with perfect channel knowledge is preserved by analog feedback and the mean loss in sum rate is bounded by a constant when signal-to-noise ratio is comparable in both forward and feedback channels. When such feedback quality is not quite possible, a fraction of the degrees of freedom is achieved. We consider the overhead of training and feedback and use this framework to optimize the system's effective throughput...

  9. An information-guided channel-hopping scheme for block-fading channels with estimation errors

    KAUST Repository

    Yang, Yuli

    2010-12-01

    Information-guided channel-hopping technique employing multiple transmit antennas was previously proposed for supporting high data rate transmission over fading channels. This scheme achieves higher data rates than some mature schemes, such as the well-known cyclic transmit antenna selection and space-time block coding, by exploiting the independence character of multiple channels, which effectively results in having an additional information transmitting channel. Moreover, maximum likelihood decoding may be performed by simply decoupling the signals conveyed by the different mapping methods. In this paper, we investigate the achievable spectral efficiency of this scheme in the case of having channel estimation errors, with optimum pilot overhead for minimum meansquare error channel estimation, when transmitting over blockfading channels. Our numerical results further substantiate the robustness of the presented scheme, even with imperfect channel state information. ©2010 IEEE.

  10. On Channels with Action-Dependent States

    CERN Document Server

    Ahmadi, Behzad

    2012-01-01

    Action-dependent channels model scenarios in which transmission takes place in two successive phases. In the first phase, the encoder selects an "action" sequence, with the twofold aim of conveying information to the receiver and of affecting in a desired way the state of the channel to be used in the second phase. In the second phase, communication takes place in the presence the mentioned action-dependent state. In this work, two extensions of the original action-dependent channel are studied. In the first, the decoder is interested in estimating not only the message, but also the state sequence within an average per-letter distortion. Under the constraint of common knowledge (i.e., the decoder's estimate of the state must be recoverable also at the encoder) and assuming non-causal state knowledge at the encoder in the second phase, we obtain a single-letter characterization of the achievable rate-distortion-cost trade-off. In the second extension, we study an action-dependent degraded broadcast channel. Un...

  11. Gaussian matrix product states for coding in bosonic communication channels

    CERN Document Server

    Schäfer, Joachim; Cerf, Nicolas J

    2012-01-01

    The communication capacity of Gaussian bosonic channels with memory has recently attracted much interest. Here, we investigate a method to prepare the multimode entangled input symbol states for encoding classical information into these channels. In particular, we study the usefulness of a Gaussian matrix product state (GMPS) [G. Adesso and M. Ericsson, Phys. Rev. A 74, 030305 (2006)] as an input symbol state, which can be sequentially generated although it remains heavily entangled for an arbitrary number of modes. We show that the GMPS can achieve more than 99.9% of the Gaussian capacity for Gaussian bosonic memory channels with a Markovian or non-Markovian correlated noise model in a large range of noise correlation strengths. Furthermore, we present a noise class for which the GMPS is the exact optimal input symbol state of the corresponding channel. Since GMPS are ground states of particular quadratic Hamiltonians, our results suggest a possible link between the theory of quantum communication channels a...

  12. Stochastic resonance in ion channels characterized by information theory.

    Science.gov (United States)

    Goychuk, I; Hänggi, P

    2000-04-01

    We identify a unifying measure for stochastic resonance (SR) in voltage dependent ion channels which comprises periodic (conventional), aperiodic, and nonstationary SR. Within a simplest setting, the gating dynamics is governed by two-state conductance fluctuations, which switch at random time points between two values. The corresponding continuous time point process is analyzed by virtue of information theory. In pursuing this goal we evaluate for our dynamics the tau information, the mutual information, and the rate of information gain. As a main result we find an analytical formula for the rate of information gain that solely involves the probability of the two channel states and their noise averaged rates. For small voltage signals it simplifies to a handy expression. Our findings are applied to study SR in a potassium channel. We find that SR occurs only when the closed state is predominantly dwelled upon. Upon increasing the probability for the open channel state the application of an extra dose of noise monotonically deteriorates the rate of information gain, i.e., no SR behavior occurs.

  13. Omni-channel Retail Information Systems

    DEFF Research Database (Denmark)

    Tambo, Torben

    2014-01-01

    and definition of omni-channel retail information systems (OCRIS) by using the information systems research tradition as a distinctive starting point (Treiblmaier and Strebinger, 2008; Avgerou, 2001; Parboteah et al., 2009). Omni-channel retailing has evolved since 2010 with the ultimate aim of aligning physical...... systems have been introduced to be able to cope with the challenges of OCRIS. However, as a business strategy, it is still evolving and not many of the actual implementations have been able to fully realise the vision....

  14. Probabilistic Teleportation via Quantum Channel with Partial Information

    Directory of Open Access Journals (Sweden)

    Desheng Liu

    2015-06-01

    Full Text Available Two novel schemes are proposed to teleport an unknown two-level quantum state probabilistically when the sender and the receiver only have partial information about the quantum channel, respectively. This is distinct from the fact that either the sender or the receiver has entire information about the quantum channel in previous schemes for probabilistic teleportation. Theoretical analysis proves that these schemes are straightforward, efficient and cost-saving. The concrete realization procedures of our schemes are presented in detail, and the result shows that our proposals could extend the application range of probabilistic teleportation.

  15. Information Equation of State

    Directory of Open Access Journals (Sweden)

    M. Paul Gough

    2008-07-01

    Full Text Available Landauer’s principle is applied to information in the universe. Once stars began forming there was a constant information energy density as the increasing proportion of matter at high stellar temperatures exactly compensated for the expanding universe. The information equation of state was close to the dark energy value, w = -1, for a wide range of redshifts, 10 > z > 0.8, over one half of cosmic time. A reasonable universe information bit content of only 1087 bits is sufficient for information energy to account for all dark energy. A time varying equation of state with a direct link between dark energy and matter, and linked to star formation in particular, is clearly relevant to the cosmic coincidence problem. In answering the ‘Why now?’ question we wonder ‘What next?’ as we expect the information equation of state to tend towards w = 0 in the future.c

  16. Information Theoretic Exemplification of the Impact of Transmitter-Receiver Cognition on the Channel Capacity

    CERN Document Server

    Anzabi-Nezhad, Nima S; Kakhki, Mohammad Molavi

    2011-01-01

    In this paper, we study, information theoretically, the impact of transmitter and or receiver cognition on the channel capacity. The cognition can be described by state information, dependent on the channel noise and or input. Specifically, as a new idea, we consider the receiver cognition as a state information dependent on the noise and we derive a capacity theorem based on the Gaussian version of the Cover-Chiang capacity theorem for two-sided state information channel. As intuitively expected, the receiver cognition increases the channel capacity and our theorem shows this increase quantitatively. Also, our capacity theorem includes the famous Costa theorem as its special cases.

  17. On the Capacity of Compound State-Dependent Channels with States Known at the Transmitter

    CERN Document Server

    Piantanida, Pablo

    2010-01-01

    This paper investigates the capacity of compound state-dependent channels with non-causal state information available at only the transmitter. A new lower bound on the capacity of this class of channels is derived. This bound is shown to be tight for the special case of compound channels with stochastic degraded components, yielding the full characterization of the capacity. Specific results are derived for the compound Gaussian Dirty-Paper (GDP) channel. This model consists of an additive white Gaussian noise (AWGN) channel corrupted by an additive Gaussian interfering signal, known at the transmitter only, where the input and the state signals are affected by fading coefficients whose realizations are unknown at the transmitter. Our bounds are shown to be tight for specific cases. Applications of these results arise in a variety of wireless scenarios as multicast channels, cognitive radio and problems with interference cancellation.

  18. State transfer in intrinsic decoherence spin channels

    CERN Document Server

    Hu, Ming-Liang; 10.1140/epjd/e2009-00220-8

    2011-01-01

    By analytically solving the master equation, we investigate quantum state transfer, creation and distribution of entanglement in the model of Milburn's intrinsic decoherence. Our results reveal that the ideal spin channels will be destroyed by the intrinsic decoherence environment, and the detrimental effects become severe as the decoherence rate $\\gamma$ and the spin chain length $N$ increase. For infinite evolution time, both the state transfer fidelity and the concurrence of the created and distributed entanglement approach steady state values, which are independent of the decoherence rate $\\gamma$ and decrease as the spin chain length $N$ increases. Finally, we present two modified spin chains which may serve as near perfect spin channels for long distance state transfer even in the presence of intrinsic decoherence environments $\\mathcal {F}{[\\rho(t)]}$.

  19. Radio Channel State Prediction by Kalman Filter

    Directory of Open Access Journals (Sweden)

    Peter Ziacik

    2005-01-01

    Full Text Available In this article there is the description Kalman filter using as a radio channel state predictor. Simulator of prediction has been created in MATLAB environment and it is capable to simulate the prediction of radio signal envelope by Clark’s model of radio channel, which is implemented to the simulator. Simulations were realized for prediction range 0.41 ms and 6.24 ms and as comparing criterion we used the prediction error. It is clear from simulations, that with the duration of prediction the prediction error is enlarging, which may cause the erroneous decision of adaptation algorithms.

  20. Joint remote state preparation (JRSP) of two-qubit equatorial state in quantum noisy channels

    Science.gov (United States)

    Adepoju, Adenike Grace; Falaye, Babatunde James; Sun, Guo-Hua; Camacho-Nieto, Oscar; Dong, Shi-Hai

    2017-02-01

    This letter reports the influence of noisy channels on JRSP of two-qubit equatorial state. We present a protocol for JRSP of two-qubit equatorial state. Afterward, we investigate the effects of five quantum noises on the protocol. We find that the system loses some of its properties as consequence of unwanted interactions with environment. For instance, within the domain 0 < λ < 0.65, the information lost via transmission of qubits in amplitude channel is most minimal, while for 0.65 < λ ≤ 1, the information lost in phase flip channel becomes the most minimal. Also, for any given λ, the information transmitted through depolarizing channel has the least chance of success.

  1. Distributed Joint Source-Channel Coding on a Multiple Access Channel with Side Information

    CERN Document Server

    Rajesh, R

    2008-01-01

    We consider the problem of transmission of several distributed sources over a multiple access channel (MAC) with side information at the sources and the decoder. Source-channel separation does not hold for this channel. Sufficient conditions are provided for transmission of sources with a given distortion. The source and/or the channel could have continuous alphabets (thus Gaussian sources and Gaussian MACs are special cases). Various previous results are obtained as special cases. We also provide several good joint source-channel coding schemes for a discrete/continuous source and discrete/continuous alphabet channel. Channels with feedback and fading are also considered. Keywords: Multiple access channel, side information, lossy joint source-channel coding, channels with feedback, fading channels.

  2. Optimal transmission strategy for spatially correlated MIMO systems with channel statistical information

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhen-shan; XU Guo-zhi

    2007-01-01

    In real multiple-input multiple-output (MIMO) systems, the perfect channel state information (CSI) may be costly or impossible to acquire. But the channel statistical information can be considered relatively stationary during long-term transmission.The statistical information can be obtained at the receiver and fed back to the transmitter and do not require frequent update. By exploiting channel mean and covariance information at the transmitter simultaneously, this paper investigates the optimal transmission strategy for spatially correlated MIMO channels. An upper bound of ergodic capacity is derived and taken as the performance criterion. Simulation results are also given to show the performance improvement of the optimal transmission strategy.

  3. Bit-padding information guided channel hopping

    KAUST Repository

    Yang, Yuli

    2011-02-01

    In the context of multiple-input multiple-output (MIMO) communications, we propose a bit-padding information guided channel hopping (BP-IGCH) scheme which breaks the limitation that the number of transmit antennas has to be a power of two based on the IGCH concept. The proposed scheme prescribes different bit-lengths to be mapped onto the indices of the transmit antennas and then uses padding technique to avoid error propagation. Numerical results and comparisons, on both the capacity and the bit error rate performances, are provided and show the advantage of the proposed scheme. The BP-IGCH scheme not only offers lower complexity to realize the design flexibility, but also achieves better performance. © 2011 IEEE.

  4. Non-Markovianity and reservoir memory of quantum channels: a quantum information theory perspective.

    Science.gov (United States)

    Bylicka, B; Chruściński, D; Maniscalco, S

    2014-07-21

    Quantum technologies rely on the ability to coherently transfer information encoded in quantum states along quantum channels. Decoherence induced by the environment sets limits on the efficiency of any quantum-enhanced protocol. Generally, the longer a quantum channel is the worse its capacity is. We show that for non-Markovian quantum channels this is not always true: surprisingly the capacity of a longer channel can be greater than of a shorter one. We introduce a general theoretical framework linking non-Markovianity to the capacities of quantum channels and demonstrate how harnessing non-Markovianity may improve the efficiency of quantum information processing and communication.

  5. Non-Markovianity and reservoir memory of quantum channels: a quantum information theory perspective

    Science.gov (United States)

    Bylicka, B.; Chruściński, D.; Maniscalco, S.

    2014-01-01

    Quantum technologies rely on the ability to coherently transfer information encoded in quantum states along quantum channels. Decoherence induced by the environment sets limits on the efficiency of any quantum-enhanced protocol. Generally, the longer a quantum channel is the worse its capacity is. We show that for non-Markovian quantum channels this is not always true: surprisingly the capacity of a longer channel can be greater than of a shorter one. We introduce a general theoretical framework linking non-Markovianity to the capacities of quantum channels and demonstrate how harnessing non-Markovianity may improve the efficiency of quantum information processing and communication. PMID:25043763

  6. [Synopsis about the hypothesis of "information channel" of channel-collateral system].

    Science.gov (United States)

    Chang, Xi-Lang

    2008-10-01

    The author of the present paper founded a theorem about the "incompleteness of single channel structure" (nerve, blood vessel, lymphatic, interspace, aperture, etc.) through quantitative and qualitative analysis about the economic information channel in the human body, which eliminates the probability of single channel structure in the information channel of channel (meridian)-collateral system. After comprehensive analysis on the current researches, the author puts forward a neodoxy, i.e., the body "information channel" structure of the channel-collateral system, mainly follows the distribution regularity of systemic statistics, and is not a single specific entity; various layers of the information channel in the main stems of the channel-collaterals are composed of optimized structure tissues. Hence, the structure of this information channel of channel-collateral system is an overall-optimized, sequential and compatible systemic structure. From this neodoxy, the author brings forward a working principle of channel-collaterals, which is supported theoretically by bio-auxology. The longitudinal distribution of the main stems of meridian-collaterals is considered to result from that in the process of the animal evolution, in the animals moving forward, the microscopic complicated movement of intracorporeal information and energy molecules is related to the forward macroscopic and non-uniform movement of organism in trans-measure. Its impulse and kinetic momentum forms a main vector in the longitudinal direction of the body (the direction of the main stem of channel-collaterals). In order to adapt to and utilize natural regularities, the main stems of the channel-collaterals gradually differentiate and evolve in the living organism, forming a whole system. The "hypothesis of biological origin of channel-collateral system" and "that of information channel of the channel-collaterals in the body" constitute a relatively complete theoretical system framework.

  7. Quantum channel for the transmission of information

    Science.gov (United States)

    Dress, William B.; Kisner, Roger A.; Richards, Roger K.

    2004-01-13

    Systems and methods are described for a quantum channel for the transmission of information. A method includes: down converting a beam of coherent energy to provide a beam of multi-color entangled photons; converging two spatially resolved portions of the beam of multi-color entangled photons into a converged multi-color entangled photon beam; changing a phase of at least a portion of the converged multi-color entangled photon beam to generate a first interferometric multi-color entangled photon beam; combining the first interferometric multi-color entangled photon beam with a second interferometric multi-color entangled photon beam within a single beam splitter; wherein combining includes erasing energy and momentum characteristics from both the first interferometric multi-color entangled photon beam and the second interferometric multi-color entangled photon beam; splitting the first interferometric multi-color entangled photon beam and the second interferometric multi-color entangled photon beam within the single beam splitter, wherein splitting yields a first output beam of multi-color entangled photons and a second output beam of multi-color entangled photons; and modulating the first output beam of multi-color entangled photons.

  8. Research on Cost Information Sharing and Channel Choice in a Dual-Channel Supply Chain

    Directory of Open Access Journals (Sweden)

    Huihui Liu

    2016-01-01

    Full Text Available Many studies examine information sharing in an uncertain demand environment in a supply chain. However there is little literature on cost information sharing in a dual-channel structure consisting of a retail channel and a direct sales channel. Assuming that the retail sale cost and direct sale cost are random variables with a general distribution, the paper investigates the retailer’s choice on cost information sharing in a Bertrand competition model. Based on the equilibrium outcome of information sharing, the manufacturer’s channel choice is discussed in detail. Our paper provides several interesting conclusions. In both single- and dual-channel structures, the retailer has little motivation to share its private cost information which is verified to be valuable for the manufacturer. When the cost correlation between the two channels increases, our analyses show that the manufacturer’s profit improves. However, when channel choice is involved, the value of information could play a different role. The paper finds that a dual-channel structure can benefit the manufacturer only when the cost correlation is sufficiently low. In addition, if the cost correlation is weak, the cost fluctuation will bring out the advantage of a dual-channel structure and adding a new direct channel will help in risk pooling.

  9. Modulated Hawking radiation and a nonviolent channel for information release

    Directory of Open Access Journals (Sweden)

    Steven B. Giddings

    2014-11-01

    Full Text Available Unitarization of black hole evaporation requires that quantum information escapes a black hole; an important question is to identify the mechanism or channel by which it does so. Accurate counting of black hole states via the Bekenstein–Hawking entropy would indicate this information should be encoded in radiation with average energy flux matching Hawking's. Information can be encoded with no change in net flux via fine-grained modulation of the Hawking radiation. In an approximate effective field theory description, couplings to the stress tensor of the black hole atmosphere that depend on the internal state of the black hole are a promising alternative for inducing such modulation. These can be picturesquely thought of as due to state-dependent metric fluctuations in the vicinity of the horizon. Such couplings offer the prospect of emitting information without extra energy flux, and can be shown to do so at linear order in the couplings, with motivation given for possible extension of this result to higher orders. The potential advantages of such couplings to the stress tensor thus extend beyond their universality, which is helpful in addressing constraints from black hole mining.

  10. Gaussian matrix-product states for coding in bosonic communication channels

    Science.gov (United States)

    Schäfer, Joachim; Karpov, Evgueni; Cerf, Nicolas J.

    2012-01-01

    The communication capacity of Gaussian bosonic channels with memory has recently attracted much interest. Here, we investigate a method to prepare the multimode entangled input symbol states for encoding classical information into these channels. In particular, we study the usefulness of a Gaussian matrix-product state (GMPS) as an input symbol state, which can be sequentially generated although it remains heavily entangled for an arbitrary number of modes. We show that the GMPS can achieve more than 99.9% of the Gaussian capacity for Gaussian bosonic memory channels with a Markovian or non-Markovian correlated noise model in a large range of noise correlation strengths. Furthermore, we present a noise class for which the GMPS is the exact optimal input symbol state of the corresponding channel. Since GMPS are ground states of particular quadratic Hamiltonians, our results suggest a possible link between the theory of quantum communication channels and quantum many-body physics.

  11. Multiuser MIMO Downlink Made Practical: Achievable Rates with Simple Channel State Estimation and Feedback Schemes

    CERN Document Server

    Caire, Giuseppe; Kobayashi, Mari; Ravindran, Niranjay

    2007-01-01

    We consider a MIMO fading broadcast channel and compute achievable ergodic rates when channel state information is acquired at the receivers via downlink training and explicit channel feedback is performed to provide transmitter channel state information (CSIT). Both ``analog'' and quantized (digital) channel feedback are analyzed, and digital feedback is shown to be potentially superior when the feedback channel uses per channel coefficient is larger than 1. Also, we show that by proper design of the digital feedback link, errors in the feedback have a relatively minor effect even if simple uncoded modulation is used on the feedback channel. We extend our analysis to the case of fading MIMO Multiaccess Channel (MIMO-MAC) in the feedback link, as well as to the case of a time-varying channel and feedback delay. We show that by exploiting the MIMO-MAC nature of the uplink channel, a fully scalable system with both downlink multiplexing gain and feedback redundancy proportional to the number of base station ant...

  12. Persian Back Channel Responses in Formal versus Informal Contexts

    Directory of Open Access Journals (Sweden)

    Shahla Sharifi

    2012-01-01

    Full Text Available Utterances like /xob/ (okay, /doroste/ (right, /hmm/, /ee/, /?re/ (yeah, occur frequently in Persian conversations, but have thus far escaped from the systematic studies. Good listeners generally produce these short utterances, called "back channel responses", in appropriate times to show their participation in the conversation, but the rules governing back channeling vary from one context to another. The usage of back channel responses is different in various contexts, due to politeness or formality. This paper studies the types and functions of the back channel responses in both formal and informal settings and provides a comparison of the usage of these responses in these two kinds of contexts. The results show /bale/ (yes and /doroste/ (right are used with formal or polite verbal form, while /xob/ (okay is used with the informal style of speech and less polite verbal form. With respect to the function of back channels, signaling the understanding is the main function of back channels in informal contexts. Also, back channels signaling agreement are more frequent in formal contexts, where emotional function is less likely.

  13. Minimum decoherence cat-like states in Gaussian noisy channels

    Energy Technology Data Exchange (ETDEWEB)

    Serafini, A [Dipartimento di Fisica ' E R Caianiello' , Universita di Salerno, INFM UdR Salerno, INFN Sezione Napoli, G C Salerno, Via S Allende, 84081 Baronissi, SA (Italy); De Siena, S [Dipartimento di Fisica ' E R Caianiello' , Universita di Salerno, INFM UdR Salerno, INFN Sezione Napoli, G C Salerno, Via S Allende, 84081 Baronissi, SA (Italy); Illuminati, F [Dipartimento di Fisica ' E R Caianiello' , Universita di Salerno, INFM UdR Salerno, INFN Sezione Napoli, G C Salerno, Via S Allende, 84081 Baronissi, SA (Italy); Paris, M G A [ISIS ' A Sorbelli' , I-41026 Pavullo nel Frignano, MO (Italy)

    2004-06-01

    We address the evolution of cat-like states in general Gaussian noisy channels, by considering superpositions of coherent and squeezed coherent states coupled to an arbitrarily squeezed bath. The phase space dynamics is solved and decoherence is studied, keeping track of the purity of the evolving state. The influence of the choice of the state and channel parameters on purity is discussed and optimal working regimes that minimize the decoherence rate are determined. In particular, we show that squeezing the bath to protect a non-squeezed cat state against decoherence is equivalent to orthogonally squeezing the initial cat state while letting the bath be phase insensitive.

  14. Minimum decoherence cat-like states in Gaussian noisy channels

    CERN Document Server

    Serafini, A; Illuminati, F; Paris, M G A

    2004-01-01

    We address the evolution of cat-like states in general Gaussian noisy channels, by considering superpositions of coherent and squeezed-coherent states coupled to an arbitrarily squeezed bath. The phase space dynamics is solved and decoherence is studied keeping track of the purity of the evolving state. The influence of the choice of the state and channel parameters on purity is discussed and optimal working regimes that minimize the decoherence rate are determined. In particular, we show that squeezing the bath to protect a non squeezed cat state against decoherence is equivalent to orthogonally squeezing the initial cat state while letting the bath be phase insensitive.

  15. Information Sharing and Channel Construction of Supply Chain under Asymmetric Demand Information

    Directory of Open Access Journals (Sweden)

    Guangdong Wu

    2014-01-01

    Full Text Available Information sharing and marketing channel building have become an important problem of supply chain management theory and practice. The research of information sharing focused on traditional channel of supply chain between upstream and downstream enterprises; however, the research ignores the behavior of information sharing with potential entrants and composite structure characteristics about traditional marketing channel with the direct channel. This paper uses the model to research the effects brought about sharing demand information with potential entrants and building marketing channel, which reveals information sharing and channel building mechanism in the supply chain. The study found that the five-force model of Porter regards potential entrants only as a threat that is one-sided. When the channel competitiveness meets certain conditions, manufacturer and retailer will share demand information with potential entrants. Building composite marketing channel is the manufacturer's absolute dominant strategy. Channel construction will increase the entry barriers for potential entrants and weaken the effect of double marginalization; meanwhile, the performance of supply chain will be augmented.

  16. Quantum States as Ordinary Information

    Directory of Open Access Journals (Sweden)

    Ken Wharton

    2014-03-01

    Full Text Available Despite various parallels between quantum states and ordinary information, quantum no-go-theorems have convinced many that there is no realistic framework that might underly quantum theory, no reality that quantum states can represent knowledge about. This paper develops the case that there is a plausible underlying reality: one actual spacetime-based history, although with behavior that appears strange when analyzed dynamically (one time-slice at a time. By using a simple model with no dynamical laws, it becomes evident that this behavior is actually quite natural when analyzed “all-at-once” (as in classical action principles. From this perspective, traditional quantum states would represent incomplete information about possible spacetime histories, conditional on the future measurement geometry. Without dynamical laws imposing additional restrictions, those histories can have a classical probability distribution, where exactly one history can be said to represent an underlying reality.

  17. Absence of quantum states corresponding to unstable classical channels

    DEFF Research Database (Denmark)

    Herbst, Ira; Skibsted, Erik

    2008-01-01

    We develop a general theory of absence of quantum states corresponding to unstable classical scattering channels. We treat in detail Hamiltonians arising from symbols of degree zero in x and outline a generalization in an Appendix....

  18. The classical-quantum channel with random state parameters known to the sender

    Science.gov (United States)

    Boche, Holger; Cai, Ning; Nötzel, Janis

    2016-05-01

    We study an analog of the well-known Gel’fand Pinsker channel which uses quantum states for the transmission of the data. We consider the case where both the sender’s inputs to the channel and the channel states are to be taken from a finite set (the cq-channel with state information at the sender). We distinguish between causal and non-causal channel state information input by the sender. The receiver remains ignorant, throughout. We give a single-letter description of the capacity in the first case. In the second case we present two different regularized expressions for the capacity. It is an astonishing and unexpected result of our work that a simple change from causal to non-causal channel state information by the encoder causes the complexity of a numerical computation of the capacity formula to change from trivial to seemingly difficult. Still, even the non-single letter formula allows one to draw nontrivial conclusions, for example regarding the continuity of the capacity with respect to changes in the system parameters. The direct parts of both coding theorems are based on a special class of positive operator valued measurements (POVMs) which are derived from orthogonal projections onto certain representations of the symmetric groups. This approach supports a reasoning that is inspired by the classical method of types. In combination with the non-commutative union bound these POVMs yield an elegant method of proof for the direct part of the coding theorem in the first case.

  19. Information Models of Acupuncture Analgesia and Meridian Channels

    Directory of Open Access Journals (Sweden)

    Chang Hua Zou

    2010-12-01

    Full Text Available Acupuncture and meridian channels have been major components of Chinese and Eastern Asian medicine—especially for analgesia—for over 2000 years. In recent decades, electroacupuncture (EA analgesia has been applied clinically and experimentally. However, there were controversial results between different treatment frequencies, or between the active and the placebo treatments; and the mechanisms of the treatments and the related meridian channels are still unknown. In this study, we propose a new term of infophysics therapy and develop information models of acupuncture (or EA analgesia and meridian channels, to understand the mechanisms and to explain the controversial results, based on Western theories of information, trigonometry and Fourier series, and physics, as well as published biomedical data. We are trying to build a bridge between Chinese medicine and Western medicine by investigating the Eastern acupuncture analgesia and meridian channels with Western sciences; we model the meridians as a physiological system that is mostly constructed with interstices in or between other physiological systems; we consider frequencies, amplitudes and wave numbers of electric field intensity (EFI as information data. Our modeling results demonstrate that information regulated with acupuncture (or EA is different from pain information, we provide answers to explain the controversial published results, and suggest that mechanisms of acupuncture (or EA analgesia could be mostly involved in information regulation of frequencies and amplitudes of EFI as well as neuronal transmitters such as endorphins.

  20. Cation Selectivity in Biological Cation Channels Using Experimental Structural Information and Statistical Mechanical Simulation.

    Science.gov (United States)

    Finnerty, Justin John; Peyser, Alexander; Carloni, Paolo

    2015-01-01

    Cation selective channels constitute the gate for ion currents through the cell membrane. Here we present an improved statistical mechanical model based on atomistic structural information, cation hydration state and without tuned parameters that reproduces the selectivity of biological Na+ and Ca2+ ion channels. The importance of the inclusion of step-wise cation hydration in these results confirms the essential role partial dehydration plays in the bacterial Na+ channels. The model, proven reliable against experimental data, could be straightforwardly used for designing Na+ and Ca2+ selective nanopores.

  1. Permeation mechanism of a two-state potassium channel

    Institute of Scientific and Technical Information of China (English)

    WANG Xiangqun; ZHAO Tongjun; SONG Yang; ZHAN Yong

    2007-01-01

    A two-state hopping model was proposed to study the permeation of ion channel.The Nemst equation in equilibrium and the Michaelis-Menten relation in steady state were derived from the two-state kinetic model.The currentvoltage relationship obtained in the symmetrical solutions case was linear when the applied potential was less than 100 mV,which met Ohm's law.The conductance-concentration relationship exhibited the saturation property.Moreover,the characteristic time reaching the steady state of the KcsA channel was also discussed.

  2. Perfect Entanglement Teleportation via Two Parallel W State Channels

    Institute of Scientific and Technical Information of China (English)

    WANG Mei-Yu; YAN Feng-Li

    2011-01-01

    We present a scheme for perfectly teleporting a two-qubit entangled state via two parallel W state channels. The scheme consists of a positive operator valued measurement (POVM), classical communication and the corresponding local unitary operation. How to realize the POVM using unitary operation and projective measurement is explicitly designed.%@@ We present a scheme for perfectly teleporting a two-qubit entangled state via two parallel W state channels.The scheme consists of a positive operator valued measurement (POVM), classical communication and the corre- sponding local unitary operation.How to realize the POVM using unitary operation and projective measurement is explicitly designed.

  3. 大规模MIMO系统信道状态信息反馈开销降低方法%Channel State Information Feedback Overhead Reduction Method for Massive MIMO Systems

    Institute of Scientific and Technical Information of China (English)

    李小兵; 刘利; 景小荣

    2015-01-01

    针对大规模多输入多输出(massive-multiple input multiple output,massive MIMO)系统,结合离散余弦变换(discrete cosine yransform,DCT)和快速傅里叶变换(fast fourier transform,FFT)基,研究了基于压缩感知的信道状态信息(channel state information,CSI)反馈开销降低方法.首先在用户端,该方法基于压缩感知理论对三维(three dimension,3D) CSI采用不同稀疏基组合进行表示,进而形成两种不同的观测矩阵对其进行观测,其中方法1基于3D CSI直接形成观测矩阵,而方法2则基于垂直维CSI和水平维CSI分别形成两个中间观测矩阵,进而通过Kronecker积形成最终观测矩阵.最后,将观测值经矢量化后反馈给基站端;基站端则通过正交追踪匹配算法(orthogonal matching pursuit,OMP)重构CSI.仿真结果表明,基于两种稀疏基的组合可以使得CSI反馈开销得到大幅度降低,同时,基于方法1生成的观测矩阵所重构CSI性能明显优于基于方法2的.

  4. Irreducible Decompositions and Stationary States of Quantum Channels

    Science.gov (United States)

    Carbone, Raffaella; Pautrat, Yan

    2016-06-01

    For a quantum channel (completely positive, trace-preserving map), we prove a generalization to the infinite-dimensional case of a result by Baumgartner and Narnhofer [3]: this result is, in a probabilistic language, a decomposition of a general quantum channel into its irreducible recurrent components. More precisely, we prove that the positive recurrent subspace (i.e. the space supporting the invariant states) can be decomposed as the direct sum of supports of extremal invariant states; this decomposition is not unique, in general, but we can determine all the possible decompositions. This allows us to describe the full structure of invariant states.

  5. COHERENT INFORMATION ON THERMAL RADIATION NOISE CHANNEL: AN APPROACH OF INTEGRAL WITHIN ORDERED PRODUCT OF OPERATORS

    Institute of Scientific and Technical Information of China (English)

    陈小余; 仇佩亮

    2001-01-01

    An analytical expression is given to the coherent information of the thermal radiation signal transmitted over the thermal radiation noise channel, one of the most essential quantum Gaussian channels. Focusing on the single normal mode of the thermal radiation signal and noise, we resolve the entangled state density operator, which characterizes quantum information transmission, into a direct product of two parts, with each part being a thermal radiation density operator. The calculation is aided by the technique known as "integral within ordered product of operators".

  6. Estimation of Time-Varying Channel State Transition Probabilities for Cognitive Radio Systems by means of Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    A. Akbulut

    2012-04-01

    Full Text Available In this study, Particle Swarm Optimization is applied for the estimation of the channel state transition probabilities. Unlike most other studies, where the channel state transition probabilities are assumed to be known and/or constant, in this study, these values are realistically considered to be time-varying parameters, which are unknown to the secondary users of the cognitive radio systems. The results of this study demonstrate the following: without any a priori information about the channel characteristics, even in a very transient environment, it is quite possible to achieve reasonable estimates of channel state transition probabilities with a practical and simple implementation.

  7. Basic functions of telecommunication channel elements for successful information transmission

    Directory of Open Access Journals (Sweden)

    Milorad S. Markagić

    2011-04-01

    Full Text Available The challenge in the field of multimedia telecommunications is an attempt to integrate texts, sound, images and videos coherently and consistently and to ensure simplicity and interactivity of operation. In order to make the proposed multimedia applications acceptable to end-users, the quality of transmission through the network and message presentation should have special attention. The main aims of this paper are the introduction to the communication channel with its basic elements, a detailed description of the information source and the presentation of possible approaches to the analysis of the telecommunication channel. Introduction In the age of mass application of various communication means, end-users of telecommunication channel elements rarely pay attention to the processes taking place in everyday communication and the elements presented in the channel. In order to discuss all the factors that influence the establishment and maintenance of the links, this paper will explain the basic elements of telecommunication channels. Source Every object that generates messages to be transferred to a recipient is called the source of the message. Directors, writers, speakers, books, newspapers, various instruments (thermometer, barometer, ammeter, etc., computers, a man himself - these are all sources of various messages. In relation to facilities that generate messages, there are different sources of messages. All the messages that they generate belong to discrete or continuous modes of messages. Discrete messages can be presented with element sets, where elements can be considered through different values of observed messages. Each text message of arbitrary length, for example, is made of a finite number of elements - symbols (letters, numbers, punctuation marks, from the set of symbols called the alphabet message source. Continuous messages can be presented with an infinite number of sets of elements where elements can have different values of

  8. Three-Receiver Broadcast Channels with Side Information

    CERN Document Server

    Hajizadeh, Saeed

    2012-01-01

    Three-receiver broadcast channel (BC) is of interest due to its information theoretical differences with two receiver one. In this paper, we derive achievable rate regions for two classes of 3-receiver BC with side information available at the transmitter, Multilevel BC and 3-receiver less noisy BC, by using superposition coding, Gel'fand-Pinsker binning scheme and Nair-El Gamal indirect decoding. Our rate region for multilevel BC subsumes the Steinberg rate region for 2-receiver degraded BC with side information as its special case. We also find the capacity region of 3-receiver less noisy BC when side information is available both at the transmitter and at the receivers.

  9. Cognitive relaying and power allocation under channel state uncertainties

    KAUST Repository

    Pandarakkottilil, Ubaidulla

    2013-04-01

    In this paper, we present robust joint relay precoder designs and transceiver power allocations for a cognitive radio network under imperfect channel state information (CSI). The secondary (or cognitive) network consists of a pair of single-antenna transceiver nodes and a non-regenerative two-way relay with multiple antennas which aids the communication process between the transceiver pair. The secondary nodes share the spectrum with a licensed primary user (PU) while guaranteeing that the interference to the PU receiver is maintained below a specified threshold. We consider two robust designs: the first is based on the minimization of the total transmit power of the secondary relay node required to provide the minimum quality of service, measured in terms of mean-square error (MSE) of the transceiver nodes, and the second is based on the minimization of the sum-MSE of the transceiver nodes. The robust designs are based on worst-case optimization and take into account known parameters of the error in the CSI to render the performance immune to the presence of errors in the CSI. Though the original problem is non-convex, we show that the proposed designs can be reformulated as tractable convex optimization problems that can be solved efficiently. We illustrate the performance of the proposed designs through some selected numerical simulations. © 2013 IEEE.

  10. Information-theoretically Secret Key Generation for Fading Wireless Channels

    CERN Document Server

    Ye, Chunxuan; Reznik, Alex; Shah, Yogendra; Trappe, Wade; Mandayam, Narayan

    2009-01-01

    The multipath-rich wireless environment associated with typical wireless usage scenarios is characterized by a fading channel response that is time-varying, location-sensitive, and uniquely shared by a given transmitter-receiver pair. The complexity associated with a richly scattering environment implies that the short-term fading process is inherently hard to predict and best modeled stochastically, with rapid decorrelation properties in space, time and frequency. In this paper, we demonstrate how the channel state between a wireless transmitter and receiver can be used as the basis for building practical secret key generation protocols between two entities. We begin by presenting a scheme based on level crossings of the fading process, which is well-suited for the Rayleigh and Rician fading models associated with a richly scattering environment. Our level crossing algorithm is simple, and incorporates a self-authenticating mechanism to prevent adversarial manipulation of message exchanges during the protoco...

  11. Remote State Preparation via a Non-Maximally Entangled Channel

    Institute of Scientific and Technical Information of China (English)

    郑亦庄; 顾永建; 郭光灿

    2002-01-01

    We investigate remote state preparation (RSP) via a non-maximally entangled channel for three cases: a general qubit; a special ensemble of qubits (qubit states on the equator of the Bloch sphere); and an asymptotic limit of N copies ofa general state. The results show that the classical communication cost of RSP for the two latter cases can be less than that of teleportation, but for the first case, in a restricted setting, the classical communication cost is equal to that of teleportation. Whether or not this is the case for a more general setting is still an open question.

  12. Conservation implications of amphibian habitat relationships within channelized agricultural headwater streams in the midwestern United States

    Science.gov (United States)

    The widespread use of stream channelization and subsurface tile drainage for removing water from agricultural fields has led to the development of numerous channelized agricultural headwater streams within agricultural watersheds of the Midwestern United States. Channelized agricultural headwater s...

  13. State Policy Against Information War

    Directory of Open Access Journals (Sweden)

    Dmitry Shibaev

    2016-01-01

    Full Text Available The most recent and effective method to resolve aconflict between countries is information war. Information warfare, i.e. propaganda, information sabotage, blackmail, could be more damaging than the effects of the traditional methods of war. The government must be prepared to prevent and counteract the bleeding-edge techniques of warfare that is to work out measures, to oppose enemy’s information weapons , to gain information superiority , to develop a society thatis immune to disinformation, to elaborate a concept of information warfare counteraction.The authors have examined both foreign and Russian sources of law which define the requirements for the government activities to oppose information warfare. They also refer to the opinions of foreign and Russian researchers, politicians and public figures who have commented on the concept and features of such political and legal constructs as information warfare and information weapons. The problem of information warfare must be identified as a profoundly serious and damaging threat. This paper provides the features of information warfare and the methods to resist it as well as the proposals to amend the domestic legislation to create conditions for an accurate understanding of this political and legal phenomenon. In addition, it points out that the amendment of the Information Security Doctrine is not sufficient to counterbalance the threat of information warfare. In a certain document it is necessary to recount all notions, requirements and methods for the government actions aimed to gradually change the situation, particularly, the development of sectoral (information security legislation, specialists training to be able to deal with informational and psychological aggression forming public opinion through the government-run mass media, etc.

  14. Lower Bounds on the Capacity of the Relay Channel with States at the Source

    Directory of Open Access Journals (Sweden)

    Abdellatif Zaidi

    2009-01-01

    Full Text Available We consider a state-dependent three-terminal full-duplex relay channel with the channel states noncausally available at only the source, that is, neither at the relay nor at the destination. This model has application to cooperation over certain wireless channels with asymmetric cognition capabilities and cognitive interference relay channels. We establish lower bounds on the channel capacity for both discrete memoryless (DM and Gaussian cases. For the DM case, the coding scheme for the lower bound uses techniques of rate-splitting at the source, decode-and-forward (DF relaying, and a Gel'fand-Pinsker-like binning scheme. In this coding scheme, the relay decodes only partially the information sent by the source. Due to the rate-splitting, this lower bound is better than the one obtained by assuming that the relay decodes all the information from the source, that is, full-DF. For the Gaussian case, we consider channel models in which each of the relay node and the destination node experiences on its link an additive Gaussian outside interference. We first focus on the case in which the links to the relay and to the destination are corrupted by the same interference; and then we focus on the case of independent interferences. We also discuss a model with correlated interferences. For each of the first two models, we establish a lower bound on the channel capacity. The coding schemes for the lower bounds use techniques of dirty paper coding or carbon copying onto dirty paper, interference reduction at the source and decode-and-forward relaying. The results reveal that, by opposition to carbon copying onto dirty paper and its root Costa's initial dirty paper coding (DPC, it may be beneficial in our setup that the informed source uses a part of its power to partially cancel the effect of the interference so that the uninformed relay benefits from this cancellation, and so the source benefits in turn.

  15. Information extraction from the GER 63-channel spectrometer data

    Science.gov (United States)

    Kiang, Richard K.

    1993-09-01

    The unprecedented data volume in the era of NASA's Mission to Planet Earth (MTPE) demands innovative information extraction methods and advanced processing techniques. The neural network techniques, which are intrinsic to distributed parallel processings and have shown promising results in analyzing remotely sensed data, could become the essential tools in the MTPE era. To evaluate the information content of data with higher dimension and the usefulness of neural networks in analyzing them, measurements from the GER 63-channel airborne imaging spectrometer data over Cuprite, Nevada, are used. The data are classified with 3-layer Perceptron of various architectures. It is shown that the neural network can achieve a level of performance similar to conventional methods, without the need for an explicit feature extraction step.

  16. Efficient Quantum Information Transfer Through a Uniform Channel

    Directory of Open Access Journals (Sweden)

    Paola Verrucchi

    2011-06-01

    Full Text Available Effective quantum-state and entanglement transfer can be obtained by inducing a coherent dynamics in quantum wires with homogeneous intrawire interactions. This goal is accomplished by optimally tuning the coupling between the wire endpoints and the two qubits there attached. A general procedure to determine such value is devised, and scaling laws between the optimal coupling and the length of the wire are found. The procedure is implemented in the case of a wire consisting of a spin-1/2 XY chain: results for the time dependence of the quantities which characterize quantum-state and entanglement transfer are found of extremely good quality also for very long wires. The present approach does not require engineered intrawire interactions nor a specific initial pulse shaping, and can be applied to a vast class of quantum channels.

  17. INFORMATION CHARACTERIZATION OF COMMUNICATION CHANNELS FOR SYSTEM IDENTIFICATION

    Institute of Scientific and Technical Information of China (English)

    Le Yi WANG; G. George YIN

    2007-01-01

    This paper studies identification of systems in which the system output is quantized,transmitted through a digital communication channel, and observed afterwards. The concept of the CR Ratio is introduced to characterize impact of communication channels on identification. The relationship between the CR Ratio and Shannon channel capacity is discussed. Identification algorithms are further developed when the channel error probability is unknown.

  18. Teleportation of a multiqubit state by an entangled qudit channel

    Institute of Scientific and Technical Information of China (English)

    郑亦庄; 顾永建; 吴桂初; 郭光灿

    2003-01-01

    We investigate the problem of teleportation of an M-qubit state by using an entangled qudit pair as a quantum channe; and show that the teleportation of a multiparticle state can correspond to the teleportation of a multidimensional state.We also introduce a quantum-state converter composed of beamspliter arrays,on /off -detectors and coross-Kerr couplers and demonstrate that the stte concersion from an M-qubit to an N-dimensional qudit and vice versa can be implemented with this converter,where N=2M,Based on this ,an experimentallu feasible for the teleportation of an M-qubit via an entangl;ed N-level qudit pair channel is proposed.

  19. Quantum Information Splitting of Arbitrary Three-qubit State by Using Five-qubit Cluster state and GHZ-state

    Science.gov (United States)

    Yin, Aihan; Wang, Jiwei

    2016-12-01

    In this paper, a new scheme of quantum information splitting (8QIS) by using five-qubit state and GHZ-state as quantum channel is proposed. The sender Alice performs Bell-state measurements (BSMs) on her qubit-pairs respectively,then tells her measurement result to the receivers Bob. If Bob wants to reconstruct the original states, he must cooperates with the controller Charlie, that Charlie performs two single particle measurement on his qubits and tells Bob the results. According to Alice's and Bob's results, Bob can reconstruct the initial state by applying appropriate unitary operation.

  20. Remote State Preparation Using Non-Maximally Entangled State: Universality and Necessary Amount of Quantum Channels

    Institute of Scientific and Technical Information of China (English)

    MEI Yu-Xue; CHEN Lin; CHEN Yi-Xin

    2006-01-01

    @@ In a process of remote state preparation, the universality of quantum channel is an essential ingredient. That is, one quantum channel should be feasible to remotely prepare any given qubit state. This problem appears in a process where one uses non-maximally entangled state as the passage. We present a scheme in which any given qubit |φ〉 = cosθ|0〉 + sinθeiψ|1〉 could be remotely prepared by using minimum classical bits and the previously shared non-maximally entangled state with a high fidelity, under the condition that the receiver holds the knowledge of θ. This condition is helpful to reduce the necessary amount of quantum channels, which is proven to be a low quantity to realize the universality. We also give several methods to investigate the trade-off between this amount and the achievable fidelity of the protocol.

  1. Overview of Financial Contagion Channels in the Banking Sector of Baltic States

    Directory of Open Access Journals (Sweden)

    Laura Gudelytė

    2014-10-01

    Full Text Available AbstractThis article aims to determine and analyse the main features of channels of financial contagion in the banking sector of Baltic States. The most relevant channels seem to be the risk of common lender, the channel of real estate prices the channel of other macroeconomic shocks and the channel of volatility. This paper contributes to the further analysis of internal and external causes of financial crisis and its transmission channels in banking sector in Baltic States.Purpose To indicate and explain main problems related to the systemic risk and the channels of financial contagion in the banking sector of Baltic States.Design/methodology/approach – general overview of research papers presenting concepts and methodologies of assessment of systemic risk of the banking sector, statistical analysis of financial data.Findings determination of the main channels and extent of financial contagion that are relevant to banking sector of Baltic States.Research limitations/implications – the lack of information concerning the liquidity and asset structure of banking sector of Baltic States and the real estate prices in Baltic States. The most common problem analysing the financial contagion and systemic risk is the lack of information (especially about the structure of liabilities and assets of financial institutions, its maturity and the changing new banking regulatory conditions. Due the lack of data it is impossible to create stable and reliable statistical models describing the stochastic behaviour of financial contagion. We do not take into account the political factors concerning the reforms of financial market supervision that have also the impact on financial contagion and systemic risk ant the point of view to Baltic States of foreign investors. The findings of this article should ground the macro-prudential policy in the small countries of supervising institutions focussing on the external factors.Practical implications

  2. Quantum Decoherence Timescales for Ionic Superposition States in Ion Channels

    CERN Document Server

    Salari, V; Fazileh, F; Shahbazi, F

    2014-01-01

    There are many controversial and challenging discussions about quantum effects in microscopic structures in neurons of the human brain. The challenge is mainly because of quick decoherence of quantum states due to hot, wet and noisy environment of the brain which forbids long life coherence for brain processing. Despite these critical discussions, there are only a few number of published papers about numerical aspects of decoherence in neurons. Perhaps the most important issue is offered by Max Tegmark who has calculated decoherence times for the systems of "ions" and "microtubules" in neurons of the brain. In fact, Tegmark did not consider ion channels which are responsible for ions displacement through the membrane and are the building blocks of electrical membrane signals in the nervous system. Here, we would like to re-investigate decoherence times for ionic superposition states by using the data obtained via molecular dynamics simulations. Our main approach is according to what Tegmark has used before. I...

  3. Streamwise decay of localized states in channel flow

    CERN Document Server

    Zammert, Stefan

    2016-01-01

    Channel flow, the pressure driven flow between parallel plates, has exact coherent structures that show various degrees of localization. For states which are localized in streamwise direction but extended in spanwise direction, we show that they are exponentially localized, with decay constants that are different on the upstream and downstream side. We extend the analysis of Brand and Gibson, J. Fluid Mech. 750, R1 (2014), for stationary states to the case of advected structures that is needed here, and derive expressions for the decay in terms of eigenvalues and eigenfunctions of certain second order differential equations. The results are in very good agreement with observations on exact coherent structures of different transversal wave length.

  4. Information cloning of harmonic oscillator coherent states

    Indian Academy of Sciences (India)

    N D Hari Dass; Pradeep Ganesh

    2002-08-01

    We show that in the case of unknown harmonic oscillator coherent statesit is possible to achieve what we call perfect information cloning. By this we mean that it is still possible to make arbitrary number of copies of a state which has exactly the same information content as the original unknown coherent state. By making use of this perfect information cloning it would be possible to estimate the original state through measurements and make arbitrary number of copies of the estimator. We define the notion of a measurement fidelity and calculate it for our case as well as for the Gaussian cloners.

  5. Precoding Scheme for Up-link Multi-user MIMO System with Imperfect Channel State Information%上行多用户MIMO中继系统中基于不完全信道状态信息的预编码算法

    Institute of Scientific and Technical Information of China (English)

    陈小敏; 朱益民; 苏君煦; 朱秋明; 胡续俊

    2016-01-01

    This paper investigates transceiver design for dual-hop up-link multi-user Multiple-Input Multiple- Output (MIMO) system with Amplify-and-Forward (AF) relay to improve the performance of Bit Error Ratio (BER) under the imperfect Channel State Information (CSI). Since the antenna correlation at both ends of the channel and the channel estimation errors are taken into account, a robust transceiver design is proposed. The optimization issue is formed with Minimum Mean-Square Error (MMSE) rule firstly. Then the relaying matrix and the optimal source precoding matrix are optimized at the maximum power constraint of the transmitter and relay station subsequently. Finally, the equalizer is optimized by a gradient-based line search algorithm. Simulation results indicate that the proposed design approach achieves better robustness against antenna correlation and channel estimation errors than existing methods.%论文研究了存在信道估计误差及天线相关条件下,上行多用户MIMO中继系统的预编码问题,目标是提升系统的误比特率性能。针对基于放大转发中继技术的上行多用户 MIMO 中继系统,考虑源-中继和中继-目的端信道中存在的信道估计误差及天线相关,提出一种基于不完全信道状态信息(Channel State Information, CSI)的预编码设计方案。首先根据最小均方误差(Minimum Mean-Squared Error, MMSE)准则设计代价函数,以发射端和中继端最大功率为约束条件,通过理论推导求得中继端和发射端的线性预编码矩阵,最后采用迭代下降法得到接收端处理矩阵的闭式解。数值仿真结果表明,在存在信道估计误差和天线相关的条件下,与现有算法相比,所提算法能有效降低系统的误比特率。

  6. Achievable Information Rates on Linear Interference Channels with Discrete Input

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Forchhammer, Søren

    2015-01-01

    In this paper lower bound on the capacity of multi-dimensional linear interference channels is derived, when the input is taken from a finite size alphabet. The bounds are based on the QR decomposition of the channel matrix, and hold for any input distribution that is independent across dimensions...

  7. Side Channel Passive Quantum Key Distribution with One Uninformative State

    Science.gov (United States)

    Kang, Guo-Dong; Zhou, Qing-Ping; Fang, Mao-Fa

    2017-03-01

    In most of quantum key distribution schemes, real random number generators are required on both sides for preparation and measurement bases choice. In this paper, via entangled photon pairs, we present a side channel passive quantum key distribution scheme, in which random number generator is unneeded on the receiver side. On the sender Alice side, along with massive of signal photons, small amount of uninformative photons are randomly sent to her partner Bob for eavesdropper-presence testing and error estimation. While on the other side channel, without using random number generator Bob do not actively measure the income signals randomly in two non-orthogonal bases. Instead, he just passively register photon click events, in two settled symmetric (i.e. X) bases, and the raw key(click events) is the probable outcomes of a special quantum measurement module constructed by Alice and Bob. Further, security analysis and formulas of security bounds for this scheme is also investigated under reasonable assumptions. Our work shows that the uninformative state employed in this paper is powerful to fight against eavesdropper Eve.

  8. Remote optimal state estimation over communication channels with random delays

    KAUST Repository

    Mahmoud, Magdi S.

    2014-01-22

    This paper considers the optimal estimation of linear systems over unreliable communication channels with random delays. In this work, it is assumed that the system to be estimated is far away from the filter. The observations of the system are capsulized without time stamp and then transmitted to the network node at which the filter is located. The probabilities of time delays are assumed to be known. The event-driven estimation scheme is applied in this paper and the estimate of the states is updated only at each time instant when any measurement arrives. To capture the feature of communication, the system considered is augmented, and the arrived measurements are regarded as the uncertain observations of the augmented system. The corresponding optimal estimation algorithm is proposed and additionally, a numerical simulation represents the performance of this work. © 2014 The authors. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  9. Hydraulic flow through a channel contraction: multiple steady states

    NARCIS (Netherlands)

    Akers, B.; Bokhove, O.

    2008-01-01

    We have investigated shallow water flows through a channel with a contraction by experimental and theoretical means. The horizontal channel consists of a sluice gate and an upstream channel of constant width $b_0$ ending in a linear contraction of minimum width $b_c$. Experimentally, we observe upst

  10. Tourism and information technologies distribution channels: a panorama of the brazilian reality

    Directory of Open Access Journals (Sweden)

    Elisete Santos da Silva Zagheni

    2011-05-01

    Full Text Available Technological evolution has made it possible that the same service may be delivered by means of multiple channels, including in the tourism sector.  The present study proposes to present a bibliographic summary of the distribution channels in tourism and the impact of information technologies (IT in these channels.  Based on exploratory research, 24 scientific papers were analyzed with the intention of identifying a research structure concerning the channels of Brazilian tourism and IT.  We observed that in Brazil, there is a lack of work concerning distribution channels in tourism, highlighting the management of these channels under the view of supply chains.  Beyond this, these papers concentrate on two elements of the channels: means of lodging and hospitality, and travel agencies.  These elements have used direct channels based on IT in order to support service activities and the commercialization of the tourist product.

  11. Information-theoretic analysis of MIMO channel sounding

    CERN Document Server

    Baum, Daniel S

    2007-01-01

    The large majority of commercially available multiple-input multiple-output (MIMO) radio channel measurement devices (sounders) is based on time-division multiplexed switching (TDMS) of a single transmit/receive radio-frequency chain into the elements of a transmit/receive antenna array. While being cost-effective, such a solution can cause significant measurement errors due to phase noise and frequency offset in the local oscillators. In this paper, we systematically analyze the resulting errors and show that, in practice, overestimation of channel capacity by several hundred percent can occur. Overestimation is caused by phase noise (and to a lesser extent frequency offset) leading to an increase of the MIMO channel rank. Our analysis furthermore reveals that the impact of phase errors is, in general, most pronounced if the physical channel has low rank (typical for line-of-sight or poor scattering scenarios). The extreme case of a rank-1 physical channel is analyzed in detail. Finally, we present measureme...

  12. TOWARDS DESIGNING A STEALTHY COMMUNICATION CHANNEL FOR HIDDEN INFORMATION

    Directory of Open Access Journals (Sweden)

    S.K. INDUMATHI,

    2011-05-01

    Full Text Available Data hiding is where the ends communicating are allowed to exchange messages abiding the security policy of the system. It transfers arbitrary bytes between two points in a fashion that would appear toolegitimate to scrutinize. Protocol Steganography transmits the messages over covert channels within network traffic packets. The most effective covert channel occurs in a data stream that looks like a non-covert network traffic with a credible purpose. The paper proposes a new approach working on the assumption that a packetmight be dropped at any moment by any intermediate node for many a reason. The need for retransmission for the dropped packet may convey the covert message to the other end of the covert channel.

  13. Remote State Preparation of Mental Information

    CERN Document Server

    Tressoldi, Patrizio E

    2012-01-01

    The aim of this paper is to define in theoretical terms and summarise the available experimental evidence that physical and mental "objects", if considered "information units", may present similar classical and quantum models of communication beyond their specific characteristics. Starting with the Remote State Preparation protocol, a variant of the Teleportation protocol, for which formal models and experimental evidence are already available in quantum mechanics, we outline a formal model applied to mental information we defined Remote State Preparation of Mental Information (RSPMI), and we summarise the experimental evidence supporting the feasibility of a RSPMI protocol. The available experimental evidence offers strong support to the possibility of real communication at distance of mental information promoting the integration between disciplines that have as their object of knowledge different aspects of reality, both physical and the mental, leading to a significant paradigm shift in cognitive and infor...

  14. Dissemination of Educational Information Through Various Media Channels.

    Science.gov (United States)

    Nimmer, Donald N.

    As a part of Project TAPE (Tactics for Applying Programs in Education), sponsored by the National Science Foundation and implemented by the University of South Dakota, mass media channels (television, newspapers, radio, educational journals, and directed mailings) were used to create awareness for new National Science Foundation-supported…

  15. Polar Decomposition of Mutual Information and Applications to Partially Coherent Channels

    CERN Document Server

    Goebel, Bernhard; Kramer, Gerhard; Winzer, Peter J; Hanik, Norbert

    2010-01-01

    The mutual information between a complex-valued channel input and its complex-valued output is decomposed into four parts based on polar coordinates: an amplitude term, a phase term, and two mixed terms. Numerical results for the additive white Gaussian noise (AWGN) channel with various inputs show that, at high signal-to-noise ratio (SNR), the amplitude and phase terms dominate the mixed terms. For the AWGN channel with a Gaussian input, analytical expressions are derived for high SNR. The decomposition method is applied to partially coherent channels and a property of such channels called "spectral loss" is developed. Spectral loss is used to explain the behavior of the capacity of nonlinear fiber-optic channels presented in recent studies, and is applied to simplify a recently published phenomenological channel model.

  16. Quantum information processing with noisy cluster states

    CERN Document Server

    Tame, M S; Kim, M S; Vedral, V

    2005-01-01

    We provide an analysis of basic quantum information processing protocols under the effect of intrinsic non-idealities in cluster states. These non-idealities are based on the introduction of randomness in the entangling steps that create the cluster state and are motivated by the unavoidable imperfections faced in creating entanglement using condensed-matter systems. Aided by the use of an alternative and very efficient method to construct cluster state configurations, which relies on the concatenation of fundamental cluster structures, we address quantum state transfer and various fundamental gate simulations through noisy cluster states. We find that a winning strategy to limit the effects of noise, is the management of small clusters processed via just a few measurements. Our study also reinforces recent ideas related to the optical implementation of a one-way quantum computer.

  17. Cloud Computing Application of Personal Information's Security in Network Sales-channels

    Directory of Open Access Journals (Sweden)

    Sun Qiong

    2013-07-01

    Full Text Available With the promotion of Internet sales, the security of personal information to network users have become increasingly demanding. The existing network of sales channels has personal information security risks, vulnerable to hacker attacking. Taking full advantage of cloud security management strategy, cloud computing security management model is introduced to the network sale of personal information security applications, which is to solve the problem of information leakage. Then we proposed membership-based cloud service provided selection policy. By exploring the prospects of cloud computing in Internet sales, we try to solve the problem of the security of personal information in this channel.

  18. Examining the Relationship Between Flexible Resources and Health Information Channel Selection.

    Science.gov (United States)

    Manierre, Matthew

    2016-01-01

    This study examines how variations in flexible resources influence where individuals begin their search for health information. Access to flexible resources such as money, power, and knowledge can alter the accessibility of channels for health information, such as doctors, the Internet, and print media. Using the HINTS 3 sample, whether information channel utilization is predicted by the same factors in two groups with distinct levels of access to flexible resources, as approximated by high and low levels of education, is investigated. Differences in access to flexible resources are hypothesized to produce variations in channel utilization in bivariate analyses, as well as changes in coefficient strength and statistical significance in multivariate models. Multinomial logit models were used to assess how a number of variables influence the probability of using a specific information channel first in either flexible resource group. Results suggest that individuals with higher levels of education, a proxy for flexible resources, are more likely to report seeking information from the Internet first, which is consistent with research on the digital divide. It appears that diminished access to flexible resources is also associated with heightened utilization of offline channels, including doctors. A handful of differences in predictors were found between the low and high flexible resource groups when multivariate models were compared. Future research should take into account the distinctions between different offline channels while also seeking to further understand how social inequality relates to the utilization of different channels and corresponding health outcomes.

  19. Generation and protection of steady-state quantum correlations due to quantum channels with memory

    Science.gov (United States)

    Guo, You-neng; Fang, Mao-fa; Wang, Guo-you; Zeng, Ke

    2016-09-01

    We have proposed a scheme of the generation and preservation of two-qubit steady-state quantum correlations through quantum channels where successive uses of the channels are correlated. Different types of noisy channels with memory, such as amplitude damping, phase damping, and depolarizing channels, have been taken into account. Some analytical or numerical results are presented. The effect of channels with memory on dynamics of quantum correlations has been discussed in detail. The results show that steady-state entanglement between two initial qubits whose initial states are prepared in a specific family states without entanglement subject to amplitude damping channel with memory can be generated. The entanglement creation is related to the memory coefficient of channel μ . The stronger the memory coefficient of channel μ is, the more the entanglement creation is, and the earlier the separable state becomes the entangled state. Besides, we compare the dynamics of entanglement with that of quantum discord when a two-qubit system is initially prepared in an entangled state. We show that entanglement dynamics suddenly disappears, while quantum discord dynamics displays only in the asymptotic limit. Furthermore, two-qubit quantum correlations can be preserved at a long time in the limit of μ → 1.

  20. Generation and protection of steady-state quantum correlations due to quantum channels with memory

    Science.gov (United States)

    Guo, You-neng; Fang, Mao-fa; Wang, Guo-you; Zeng, Ke

    2016-12-01

    We have proposed a scheme of the generation and preservation of two-qubit steady-state quantum correlations through quantum channels where successive uses of the channels are correlated. Different types of noisy channels with memory, such as amplitude damping, phase damping, and depolarizing channels, have been taken into account. Some analytical or numerical results are presented. The effect of channels with memory on dynamics of quantum correlations has been discussed in detail. The results show that steady-state entanglement between two initial qubits whose initial states are prepared in a specific family states without entanglement subject to amplitude damping channel with memory can be generated. The entanglement creation is related to the memory coefficient of channel μ . The stronger the memory coefficient of channel μ is, the more the entanglement creation is, and the earlier the separable state becomes the entangled state. Besides, we compare the dynamics of entanglement with that of quantum discord when a two-qubit system is initially prepared in an entangled state. We show that entanglement dynamics suddenly disappears, while quantum discord dynamics displays only in the asymptotic limit. Furthermore, two-qubit quantum correlations can be preserved at a long time in the limit of μ → 1.

  1. Efficient quantum dialogue using entangled states and entanglement swapping without information leakage

    Science.gov (United States)

    Wang, He; Zhang, Yu Qing; Liu, Xue Feng; Hu, Yu Pu

    2016-06-01

    We propose a novel quantum dialogue protocol by using the generalized Bell states and entanglement swapping. In the protocol, a sequence of ordered two-qutrit entangled states acts as quantum information channel for exchanging secret messages directly and simultaneously. Besides, a secret key string is shared between the communicants to overcome information leakage. Different from those previous information leakage-resistant quantum dialogue protocols, the particles, composed of one of each pair of entangled states, are transmitted only one time in the proposed protocol. Security analysis shows that our protocol can overcome information leakage and resist several well-known attacks. Moreover, the efficiency of our scheme is acceptable.

  2. Tighter Lower Bounds on Mutual Information for Fiber-Optic Channels

    CERN Document Server

    Irukulapati, Naga V; Agrell, Erik; Johannisson, Pontus; Wymeersch, Henk

    2016-01-01

    In fiber-optic communications, evaluation of mutual information (MI) is still an open issue due to the unavailability of an exact and mathematically tractable channel model. Traditionally, lower bounds on MI are computed by approximating the (original) channel with an auxiliary forward channel. In this paper, lower bounds are computed using an auxiliary backward channel, which has not been previously considered in the context of fiber-optic communications. Distributions obtained through two variations of the stochastic digital backpropagation (SDBP) algorithm are used as auxiliary backward channels and these bounds are compared with bounds obtained through the conventional digital backpropagation (DBP). Through simulations, higher information rates were achieved with SDBP compared with DBP, which implies that tighter lower bound on MI can be achieved through SDBP.

  3. Remote State Preparation of Mental Information

    OpenAIRE

    Tressoldi, Patrizio E.; Khrennikov, Andrei

    2012-01-01

    The aim of this paper is to define in theoretical terms and summarise the available experimental evidence that physical and mental "objects", if considered "information units", may present similar classical and quantum models of communication beyond their specific characteristics. Starting with the Remote State Preparation protocol, a variant of the Teleportation protocol, for which formal models and experimental evidence are already available in quantum mechanics, we outline a formal model a...

  4. Dynamics of a multi-mode maximum entangled coherent state over an amplitude damping channel

    Institute of Scientific and Technical Information of China (English)

    A. E1 Allati; Y. Hassouni; N. Metwally

    2011-01-01

    The dynamics of the maximum entangled coherent state traveling through an amplitude damping channel is investigated.For small values of the transmissivity rate,the traveling state is very fragile to this noise channel,which suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate.As the number of modes increases,the traveling state over this noise channel quickly loses its entanglement.The odd and even states vanish at the same value of field intensity.

  5. Dynamics of multi-modes maximum entangled coherent state over amplitude damping channel

    CERN Document Server

    Allati, A El; Metwally, N

    2012-01-01

    The dynamics of maximum entangled coherent state travels through an amplitude damping channel is investigated. For small values of the transmissivity rate the travelling state is very fragile to this noise channel, where it suffers from the phase flip error with high probability. The entanglement decays smoothly for larger values of the transmissivity rate and speedily for smaller values of this rate. As the number of modes increases, the travelling state over this noise channel loses its entanglement hastily. The odd and even states vanish at the same value of the field intensity.

  6. Determining the cross-channel effects of informational web sites

    NARCIS (Netherlands)

    Teerling, Marije Leonie

    2007-01-01

    This dissertation investigates the effects of an informational Web site on offline behavior, specifically with regard to customer buying behavior in a “traditional” store. This chapter serves to introduce the literature on informational Web sites (§1.2) and the multichannel environment (§1.3). It al

  7. Information channel capacity in the field theory estimation

    Energy Technology Data Exchange (ETDEWEB)

    Sładkowski, J., E-mail: jan.sladkowski@us.edu.pl [Department of Astrophysics and Cosmology, Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Syska, J., E-mail: jacek.syska@us.edu.pl [Department of Field Theory and Particle Physics, Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland)

    2012-12-03

    The construction of the information capacity for the vector position parameter in the Minkowskian space–time is presented. This lays the statistical foundations of the kinematical term of the Lagrangian of the physical action for many field theory models, derived by the extremal physical information method of Frieden and Soffer.

  8. Confidentiality & Authentication Mechanism for Biometric Information Transmitted over Low Bandwidth & Unreliable channel

    CERN Document Server

    Singh, Raju

    2011-01-01

    The security of bio-metric information - finger print, retina mapping, DNA mapping and some other chemical and biological modified genes related information - transfer through low bandwidth and unreliable or covert channel is challenging task. Therefore, Security of biometric information is essential requirement in this fast developing communication world. Thus, in this paper, we propose efficient and effective mechanism for confidentiality and authentication for biometric information transmitted by using arithmetic encoding representation over low bandwidth and unreliable channel. It enhances the speed of encryption, decryption and authentication process. It uses arithmetic encoding scheme and public key cryptography e.g. modified version of RSA algorithm called RSA-2 algorithm.

  9. Shannon's secrecy system with informed receivers and its application to systematic coding for wiretapped channels

    CERN Document Server

    Merhav, Neri

    2007-01-01

    Shannon's secrecy system is studied in a setting, where both the legitimate decoder and the wiretapper have access to side information sequences correlated to the source, but the wiretapper receives both the coded information and the side information via channels that are more noisy than the respective channels of the legitmate decoder, which in turn, also shares a secret key with the encoder. A single--letter characterization is provided for the achievable region in the space of five figures of merit: the equivocation at the wiretapper, the key rate, the distortion of the source reconstruction at the legitimate receiver, the bandwidth expansion factor of the coded channels, and the average transmission cost (generalized power). Beyond the fact that this is an extension of earlier studies, it also provides a framework for studying fundamental performance limits of systematic codes in the presence of a wiretap channel. The best achievable performance of systematic codes is then compared to that of a general co...

  10. Information leakage and steganography: detecting and blocking covert channels

    OpenAIRE

    Blasco Alís, Jorge

    2012-01-01

    This PhD Thesis explores the threat of information theft perpetrated by malicious insiders. As opposite to outsiders, insiders have access to information assets belonging the organization, know the organization infrastructure and more importantly, know the value of the different assets the organization holds. The risk created by malicious insiders have led both the research community and commercial providers to spend efforts on creating mechanisms and solutions to reduce it. However, the lack...

  11. The effect of cell size and channel density on neuronal information encoding and energy efficiency.

    Science.gov (United States)

    Sengupta, Biswa; Faisal, A Aldo; Laughlin, Simon B; Niven, Jeremy E

    2013-09-01

    Identifying the determinants of neuronal energy consumption and their relationship to information coding is critical to understanding neuronal function and evolution. Three of the main determinants are cell size, ion channel density, and stimulus statistics. Here we investigate their impact on neuronal energy consumption and information coding by comparing single-compartment spiking neuron models of different sizes with different densities of stochastic voltage-gated Na(+) and K(+) channels and different statistics of synaptic inputs. The largest compartments have the highest information rates but the lowest energy efficiency for a given voltage-gated ion channel density, and the highest signaling efficiency (bits spike(-1)) for a given firing rate. For a given cell size, our models revealed that the ion channel density that maximizes energy efficiency is lower than that maximizing information rate. Low rates of small synaptic inputs improve energy efficiency but the highest information rates occur with higher rates and larger inputs. These relationships produce a Law of Diminishing Returns that penalizes costly excess information coding capacity, promoting the reduction of cell size, channel density, and input stimuli to the minimum possible, suggesting that the trade-off between energy and information has influenced all aspects of neuronal anatomy and physiology.

  12. State Discrimination with Post-Measurement Information

    CERN Document Server

    Ballester, M A; Winter, A; Ballester, Manuel A.; Wehner, Stephanie; Winter, Andreas

    2006-01-01

    We introduce a new state discrimination problem in which we are given additional information about the state after the measurement, or more generally, after a quantum memory bound applies. In particular, the following special case plays an important role in quantum cryptographic protocols in the bounded storage model: Given a string x encoded in an unknown basis chosen from a set of mutually unbiased bases, you may perform any measurement, but then store at most q qubits of quantum information. Later on, you learn which basis was used. How well can you compute a function f(x) of x, given the initial measurement outcome, the q qubits and the additional basis information? We first show a lower bound on the success probability for any balanced function, and any number of mutually unbiased bases, beating the naive strategy of simply guessing the basis. We then show that for two bases, any Boolean function f(x) can be computed perfectly if you are allowed to store just a single qubit, independent of the number of ...

  13. Fast- or slow-inactivated state preference of Na+ channel inhibitors: a simulation and experimental study.

    Directory of Open Access Journals (Sweden)

    Robert Karoly

    2010-06-01

    Full Text Available Sodium channels are one of the most intensively studied drug targets. Sodium channel inhibitors (e.g., local anesthetics, anticonvulsants, antiarrhythmics and analgesics exert their effect by stabilizing an inactivated conformation of the channels. Besides the fast-inactivated conformation, sodium channels have several distinct slow-inactivated conformational states. Stabilization of a slow-inactivated state has been proposed to be advantageous for certain therapeutic applications. Special voltage protocols are used to evoke slow inactivation of sodium channels. It is assumed that efficacy of a drug in these protocols indicates slow-inactivated state preference. We tested this assumption in simulations using four prototypical drug inhibitory mechanisms (fast or slow-inactivated state preference, with either fast or slow binding kinetics and a kinetic model for sodium channels. Unexpectedly, we found that efficacy in these protocols (e.g., a shift of the "steady-state slow inactivation curve", was not a reliable indicator of slow-inactivated state preference. Slowly associating fast-inactivated state-preferring drugs were indistinguishable from slow-inactivated state-preferring drugs. On the other hand, fast- and slow-inactivated state-preferring drugs tended to preferentially affect onset and recovery, respectively. The robustness of these observations was verified: i by performing a Monte Carlo study on the effects of randomly modifying model parameters, ii by testing the same drugs in a fundamentally different model and iii by an analysis of the effect of systematically changing drug-specific parameters. In patch clamp electrophysiology experiments we tested five sodium channel inhibitor drugs on native sodium channels of cultured hippocampal neurons. For lidocaine, phenytoin and carbamazepine our data indicate a preference for the fast-inactivated state, while the results for fluoxetine and desipramine are inconclusive. We suggest that

  14. Rényi entropy measure of noise-aided information transmission in a binary channel.

    Science.gov (United States)

    Chapeau-Blondeau, François; Rousseau, David; Delahaies, Agnès

    2010-05-01

    This paper analyzes a binary channel by means of information measures based on the Rényi entropy. The analysis extends, and contains as a special case, the classic reference model of binary information transmission based on the Shannon entropy measure. The extended model is used to investigate further possibilities and properties of stochastic resonance or noise-aided information transmission. The results demonstrate that stochastic resonance occurs in the information channel and is registered by the Rényi entropy measures at any finite order, including the Shannon order. Furthermore, in definite conditions, when seeking the Rényi information measures that best exploit stochastic resonance, then nontrivial orders differing from the Shannon case usually emerge. In this way, through binary information transmission, stochastic resonance identifies optimal Rényi measures of information differing from the classic Shannon measure. A confrontation of the quantitative information measures with visual perception is also proposed in an experiment of noise-aided binary image transmission.

  15. Slow conversions among subconductance states of cystic fibrosis transmembrane conductance regulator chloride channel.

    OpenAIRE

    Tao, T.; Xie, J; Drumm, M L; Zhao, J.; Davis, P B; Ma, J.

    1996-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel exhibits multiple subconductance states. To study the regulation of conductance states of the CFTR channel, we expressed the wild-type CFTR protein in HEK 293 cells, and isolated microsomal membrane vesicles for reconstitution studies in lipid bilayer membranes. A single CFTR channel had a dominant conductance of 7.8 pS (H), plus two sub-open states with conductances of approximately 6 pS (M) and 2.7 pS (L) in 200...

  16. Dynamic State Transitions in the Nervous System: From Ion Channels to Neurons to Networks

    Science.gov (United States)

    Århem, Peter; Braun, Hans A.; Huber, Martin T.; Liljenström, Hans

    The following sections are included: * Introduction * Ion channels: The microscopic scale * The variety of ion channels * Channel kinetics * Neurons: The mesoscopic scale * The feedback loops between membrane potential and ion currents * Neuron models: Concepts and examples * Impulse pattern modulation by ion channel densities * Oscillatory patterns * Irregular patterns * Impulse pattern modulation by subthreshold oscillations * The cold receptor model * Deterministic patterns and noise induced state-transitions on temperature scaling * Neuronal networks: The oscopic scale * Random channel events cause network state transitions * A hippocampal neural network model * Simulating noise-induced state transitions * Functional significance of oscopic neurodynamics * Conclusions * Appendix A: Computation of the neuron models * Hippocampal neuron model * The cold receptor model * Appendix B: Neural network model * References

  17. Trap states in AlGaN channel high-electron-mobility transistors

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, ShengLei; Zhang, Kai; Ha, Wei; Chen, YongHe; Zhang, Peng; Zhang, JinCheng; Hao, Yue, E-mail: yhao@xidian.edu.cn [Key Laboratory of Wide Band Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China); Ma, XiaoHua, E-mail: xhma@xidian.edu.cn [Key Laboratory of Wide Band Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China); School of Advanced Materials and Nanotechnology, Xidian University, Xi' an 710071 (China)

    2013-11-18

    Frequency dependent capacitance and conductance measurements were performed to analyze the trap states in the AlGaN channel high-electron-mobility transistors (HEMTs). The trap state density in the AlGaN channel HEMTs decreases from 1.26 × 10{sup 13} cm{sup −2}eV{sup −1} at the energy of 0.33 eV to 4.35 × 10{sup 11} cm{sup −2}eV{sup −1} at 0.40 eV. Compared with GaN channel HEMTs, the trap states in the AlGaN channel HEMTs have deeper energy levels. The trap with deeper energy levels in the AlGaN channel HEMTs is another reason for the reduction of the reverse gate leakage current besides the higher Schottky barrier height.

  18. Formal and Informal Communication Channels in Creating Corporate Brand Image and Preference

    Directory of Open Access Journals (Sweden)

    Ivana First

    2011-06-01

    Full Text Available This study analyzes the effect that various communication channels have on corporate brand image creation among potential employees. Empirical data was collected by a survey conducted on a sample of 370 graduate students. The results revealed that more than ¾ of potential employees learn about the studied company through informal communication channels. Nevertheless, students of the faculties which organize formal company presentations are much better acquainted with such companies than the students of faculties where no formal presentations are held. Furthermore, within the scope of mono-channeled communication, there is no difference in the manner in which formal and informal channels influence brand knowledge and feelings. On the other hand, multi-channeled communication has a greater influence on both knowledge and feelings than mono-channeled communication. Finally, brand feelings are a stronger factor than brand knowledge in determining brand preference but knowledge also determines feelings. These results have several practical implications. Although informal communication has a wider range of resonance, formal communication is more important and should not be neglected by practitioners. Formal communication is not only able to create positive brand image equally well but it also acts as a trigger for informal communication. Practitioners facing limited resources are further advised to give priority to the communication that creates brand feelings rather than brand knowledge.

  19. Competition of information channels in the spreading of innovations

    Science.gov (United States)

    Kocsis, Gergely; Kun, Ferenc

    2011-08-01

    We study the spreading of information on technological developments in socioeconomic systems where the social contacts of agents are represented by a network of connections. In the model, agents get informed about the existence and advantages of new innovations through advertising activities of producers, which are then followed by an interagent information transfer. Computer simulations revealed that varying the strength of external driving and of interagent coupling, furthermore, the topology of social contacts, the model presents a complex behavior with interesting novel features: On the macrolevel the system exhibits logistic behavior typical for the diffusion of innovations. The time evolution can be described analytically by an integral equation that captures the nucleation and growth of clusters of informed agents. On the microlevel, small clusters are found to be compact with a crossover to fractal structures with increasing size. The distribution of cluster sizes has a power-law behavior with a crossover to a higher exponent when long-range social contacts are present in the system. Based on computer simulations we construct an approximate phase diagram of the model on a regular square lattice of agents.

  20. Calculation of mutual information for nonlinear communication channel at large signal-to-noise ratio

    Science.gov (United States)

    Terekhov, I. S.; Reznichenko, A. V.; Turitsyn, S. K.

    2016-10-01

    Using the path-integral technique we examine the mutual information for the communication channel modeled by the nonlinear Schrödinger equation with additive Gaussian noise. The nonlinear Schrödinger equation is one of the fundamental models in nonlinear physics, and it has a broad range of applications, including fiber optical communications—the backbone of the internet. At large signal-to-noise ratio we present the mutual information through the path-integral, which is convenient for the perturbative expansion in nonlinearity. In the limit of small noise and small nonlinearity we derive analytically the first nonzero nonlinear correction to the mutual information for the channel.

  1. Bidirectional and Asymmetric Controlled Quantum Information Transmission via Five-qubit Brown State

    Science.gov (United States)

    Fang, Sheng-hui; Jiang, Min

    2017-02-01

    We put forward a new protocol of deterministic controlled bidirectional quantum information transmission, using a five-qubit Brown state. That is to say Alice wants to teleport an arbitrary single-qubit state to Bob and Bob wants to remotely prepare a known state for Alice via the control of the supervisor Charlie. In terms of physical implementations, only a CNOT gate, one Bell-state measurement and one qubit measurement are used in our protocol. Compared with previous study for solely bidirectional quantum teleportation and solely bidirectional remote state preparation schemes, our protocol is a kind of hybrid approach of information communication which makes the quantum channel multipurpose, i.e., no matter whether the transmitted state is known or unknown, the state information can be transmitted with each other via a five-qubit Brown state under the control of the third party as a supervisor.

  2. State-to-state mode selectivity in the HD + OH reaction: Perspectives from two product channels

    Science.gov (United States)

    Zhao, Bin; Sun, Zhigang; Guo, Hua

    2016-06-01

    The state-to-state quantum dynamics (Jtot = 0) of the HD + OH(υ2 = 0, 1) reaction is studied using a reactant coordinate based method, which allows the analysis of both the H + DOH and D + HOH channels with a single propagation. The stretching vibration of the newly formed bond, namely, the OD bond in DOH and one OH bond in HOH, is excited, thanks to its strong coupling with the reaction coordinate at the transition state. On the other hand, the vibrational energy deposited into the OH reactant (υ2 = 1) is sequestered during the reaction in the spectator OH mode. The combined effect leads to the excitation of both the OD and OH stretching modes in the DOH product, and the dominance of the (002) normal-mode state population in the HOH product, which in the local-mode picture corresponds to the excitation of both OH bonds with one quantum each. The energy flow in this prototypical tetratomic reaction can be understood in terms of the sudden vector projection model.

  3. Quantum ballistic transport by interacting two-electron states in quasi-one-dimensional channels

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Danhong [Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117 (United States); Center for High Technology Materials, University of New Mexico, 1313 Goddard St SE, Albuquerque, New Mexico 87106 (United States); Gumbs, Godfrey [Center for High Technology Materials, University of New Mexico, 1313 Goddard St SE, Albuquerque, New Mexico 87106 (United States); Abranyos, Yonatan [Department of Physics and Astronomy, Hunter College of the City University of New York, 695 Park Avenue, New York, New York 10065 (United States); Pepper, Michael; Kumar, Sanjeev [Department of Electronic and Electrical Engineering, University College London, London, WC1E 7JE (United Kingdom); London Centre for Nanotechnology, 17-19 Gordon Street, London, WC1H 0AH (United Kingdom)

    2015-11-15

    For quantum ballistic transport of electrons through a short conduction channel, the role of Coulomb interaction may significantly modify the energy levels of two-electron states at low temperatures as the channel becomes wide. In this regime, the Coulomb effect on the two-electron states is calculated and found to lead to four split energy levels, including two anticrossing-level and two crossing-level states. Moreover, due to the interplay of anticrossing and crossing effects, our calculations reveal that the ground two-electron state will switch from one anticrossing state (strong confinement) to a crossing state (intermediate confinement) as the channel width gradually increases and then back to the original anticrossing state (weak confinement) as the channel width becomes larger than a threshold value. This switching behavior leaves a footprint in the ballistic conductance as well as in the diffusion thermoelectric power of electrons. Such a switching is related to the triple spin degeneracy as well as to the Coulomb repulsion in the central region of the channel, which separates two electrons away and pushes them to different channel edges. The conductance reoccurrence region expands from the weak to the intermediate confinement regime with increasing electron density.

  4. An Achievability Scheme for the Compound Channel with State Noncausally Available at the Encoder

    CERN Document Server

    Nair, Chandra; Chia, Yeow-Khiang

    2010-01-01

    A new achievability scheme for the compound channel with discrete memoryless (DM) state noncausally available at the encoder is established. Achievability is proved using superposition coding, Marton coding, joint typicality encoding, and indirect decoding. The scheme is shown to achieve strictly higher rate than the straightforward extension of the Gelfand-Pinsker coding scheme for a single DMC with DM state, and is optimal for some classes of channels.

  5. Cystic Fibrosis Transmembrane Conductance Regulator (CFTR): CLOSED AND OPEN STATE CHANNEL MODELS.

    Science.gov (United States)

    Corradi, Valentina; Vergani, Paola; Tieleman, D Peter

    2015-09-18

    The cystic fibrosis transmembrane conductance regulator (CFTR) is a member of the ATP-binding cassette (ABC) transporter superfamily. CFTR controls the flow of anions through the apical membrane of epithelia. Dysfunctional CFTR causes the common lethal genetic disease cystic fibrosis. Transitions between open and closed states of CFTR are regulated by ATP binding and hydrolysis on the cytosolic nucleotide binding domains, which are coupled with the transmembrane (TM) domains forming the pathway for anion permeation. Lack of structural data hampers a global understanding of CFTR and thus the development of "rational" approaches directly targeting defective CFTR. In this work, we explored possible conformational states of the CFTR gating cycle by means of homology modeling. As templates, we used structures of homologous ABC transporters, namely TM(287-288), ABC-B10, McjD, and Sav1866. In the light of published experimental results, structural analysis of the transmembrane cavity suggests that the TM(287-288)-based CFTR model could correspond to a commonly occupied closed state, whereas the McjD-based model could represent an open state. The models capture the important role played by Phe-337 as a filter/gating residue and provide structural information on the conformational transition from closed to open channel.

  6. Slow conversions among subconductance states of cystic fibrosis transmembrane conductance regulator chloride channel.

    Science.gov (United States)

    Tao, T; Xie, J; Drumm, M L; Zhao, J; Davis, P B; Ma, J

    1996-02-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel exhibits multiple subconductance states. To study the regulation of conductance states of the CFTR channel, we expressed the wild-type CFTR protein in HEK 293 cells, and isolated microsomal membrane vesicles for reconstitution studies in lipid bilayer membranes. A single CFTR channel had a dominant conductance of 7.8 pS (H), plus two sub-open states with conductances of approximately 6 pS (M) and 2.7 pS (L) in 200 mM KCl with 1 mM MgCl2 (intracellular) and 50 mM KCl with no MgCl2 (extracellular), with pH maintained at 7.4 by 10 mM HEPES-Tris on both sides of the channel. In 200 mM KCl, both H and L states could be measured in stable single-channel recordings, whereas M could not. Spontaneous transitions between H and L were slow; it took 4.5 min for L-->H, and 3.2 min for H-->L. These slow conversions among subconductance states of the CFTR channel were affected by extracellular Mg; in the presence of millimolar Mg, the channel remained stable in the H state. Similar phenomena were also observed with endogenous CFTR channels in T84 cells. In high-salt conditions (1.5 M KCl), all three conductance states of the expressed CFTR channel, 12.1 pS, 8.2 pS, and 3.6 pS, became stable and seemed to gate independently from each other. The existence of multiple stable conductance states associated with the CFTR channel suggests two possibilities: either a single CFTR molecule can exist in multiple configurations with different conductance values, or the CFTR channel may contain multimers of the 170-kDa CFTR protein, and different conductance states are due to different aggregation states of the CFTR protein.

  7. The feature on the posterior conditional probability of finite state Markov channel

    Institute of Scientific and Technical Information of China (English)

    MU Li-hua; SHEN Ji-hong; YUAN Yan-hua

    2005-01-01

    The feature of finite state Markov channel probability distribution is discussed on condition that original I/O are known. The probability is called posterior condition probability. It is also proved by Bayes formula that posterior condition probability forms stationary Markov sequence if channel input is independently and identically distributed. On the contrary, Markov property of posterior condition probability isn' t kept if the input isn't independently and identically distributed and a numerical example is utilized to explain this case. The properties of posterior condition probability will aid the study of the numerical calculated recurrence formula of finite state Markov channel capacity.

  8. Most robust and fragile two-qubit entangled states under depolarizing channels

    CERN Document Server

    Pang, Chao-Qian; Jiang, Yue; Liang, Mai-Lin

    2012-01-01

    In the two-qubit system under the local depolarizing channels, the most robust and the most fragile states for a given concurrence or negativity are derived. For the one-sided channel, with the aid of the evolution equation for entanglement given by Konrad \\emph{et al.} [Nat. Phys. 4, 99 (2008)], the pure states are proved to be the most robust. Based on a generalization of the evolution equation, we classify the ansatz states in our investigation by the amount of robustness, and consequently derive the most fragile states. For the two-sided channel, the pure states are proved to be the most robust for a fixed concurrence, but is the most fragile with a given negativity when the channel is uniform. Under the uniform channel, for a given negativity, the most robust states are the ones with the maximal concurrence, which are also the most fragile states when the concurrence is given in the region of [1/2,1]. When the entanglement approaches zero, the most fragile states for a given negativity become the pure st...

  9. 中继网络中不准确信道状态信息下抗多窃听者的物理层安全方案%Physical Layer Security Scheme Resistant to Multi-eavesdroppers with Inaccurate Channel State Information in Relay Network

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    This paper investigates the relay transmission system in the presence of multiple collusion single-antenna eavesdroppers. A physical layer security scheme employing nullspace Artificial Noise (AN) and Amplify-and-Forward (AF) relay beamforming is designed. In the case that channel state information can not be accurately obtained, the weighted matrice of relay beamforming and the nullspace AN covariance are jointed optimized based on the Semi-Definite Programs (SDP), which can effectively reduce the amount of the information likely to be obtained by the multiple collusion eavesdroppers and significantly improve the security capacity of the system. It is an effective physical security transmission scheme with good robustness. Simulation results verify that the scheme has good performance.%该文研究存在多个相互勾结的单天线窃听者的多中继传输系统中,采用零空间人工噪声和放大转发的中继波束赋形的物理层安全传输方案。在中继—窃听端的信道状态信息不准确的情况下,基于半定规划理论,对中继的波束赋形加权矩阵和人工噪声协方差矩阵进行联合优化,有效减少相互勾结的多个窃听者所获得的信息量,显著提高系统保密容量,是一种具有良好鲁棒性的物理层安全传输方案。仿真结果显示方案具有良好的性能。

  10. The Channels and Demands Analysis for Chinese Farmers’ Agricultural Information Acquisition

    Directory of Open Access Journals (Sweden)

    Zhensheng Tao

    2012-06-01

    Full Text Available This paper studies the characteristics of information sources and farmers’ demand for agricultural information in the process of agricultural informationization in China. We point out that it is not common for farmers to adopt modern information technology communication tools in rural areas nowadays, and the reason for this phenomenon is that farmers still rely mainly on traditional channels for information dissemination. To change the status quo, our government should respect farmers as dominant statuses in the process of agricultural informationization and encourage households with large-scale agricultural operation to use modern IT products in order to spread agricultural information in rural areas.

  11. State-dependent blocker interactions with the CFTR chloride channel: implications for gating the pore.

    Science.gov (United States)

    Linsdell, Paul

    2014-12-01

    Chloride permeation through the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel is subject to voltage-dependent open-channel block by a diverse range of cytoplasmic anions. However, in most cases the ability of these blocking substances to influence the pore opening and closing process has not been reported. In the present work, patch clamp recording was used to investigate the state-dependent block of CFTR by cytoplasmic Pt(NO2)4(2-) ions. Two major effects of Pt(NO2)4(2-) were identified. First, this anion caused fast, voltage-dependent block of open channels, leading to an apparent decrease in single-channel current amplitude. Secondly, Pt(NO2)4(2-) also decreased channel open probability due to an increase in interburst closed times. Interestingly, mutations in the pore that weakened (K95Q) or strengthened (I344K, V345K) interactions with Pt(NO2)4(2-) altered blocker effects both on Cl(-) permeation and on channel gating, suggesting that both these effects are a consequence of Pt(NO2)4(2-) interaction with a single site within the pore. Experiments at reduced extracellular Cl(-) concentration hinted that Pt(NO2)4(2-) may have a third effect, possibly increasing channel activity by interfering with channel closure. These results suggest that Pt(NO2)4(2-) can enter from the cytoplasm into the pore inner vestibule of both open and closed CFTR channels, and that Pt(NO2)4(2-) bound in the inner vestibule blocks Cl(-) permeation as well as interfering with channel opening and, perhaps, channel closure. Implications for the location of the channel gate in the pore, and the operation of this gate, are discussed.

  12. 76 FR 19310 - Information Collection; Certified State Mediation Program

    Science.gov (United States)

    2011-04-07

    ... Farm Service Agency Information Collection; Certified State Mediation Program AGENCY: Farm Service... Mediation Program. The information collection is necessary to ensure the grant program is being administered... following methods: Mail: Carol Wagner, Certified State Mediation Program Manager, USDA, FSA, Appeals...

  13. Optimal state estimation over communication channels with random delays

    KAUST Repository

    Mahmoud, Magdi S.

    2013-04-01

    This paper is concerned with the optimal estimation of linear systems over unreliable communication channels with random delays. The measurements are delivered without time stamp, and the probabilities of time delays are assumed to be known. Since the estimation is time-driven, the actual time delays are converted into virtual time delays among the formulation. The receiver of estimation node stores the sum of arrived measurements between two adjacent processing time instants and also counts the number of arrived measurements. The original linear system is modeled as an extended system with uncertain observation to capture the feature of communication, then the optimal estimation algorithm of systems with uncertain observations is proposed. Additionally, a numerical simulation is presented to show the performance of this work. © 2013 The Franklin Institute.

  14. Partial relay selection based on shadowing side information over generalized composite fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2011-11-01

    In this paper, in contrast to the relay selection protocols available in the literature, we propose a partial relay selection protocol utilizing only the shadowing side information of the relays instead of their full channel side information in order to select a relay in a dual-hop relaying system through the available limited feedback channels and power budget. We then presented an exact unified performance expression combining the average bit error probability, ergodic capacity, and moments-generating function of the proposed partial relay selection over generalized fading channels. Referring to the unified performance expression introduced in [1], we explicitly offer a generic unified performance expression that can be easily calculated and that is applicable to a wide variety of fading scenarios. Finally, as an illustration of the mathematical formalism, some numerical and simulation results are generated for an extended generalized-K fading environment, and these numerical and simulation results are shown to be in perfect agreement. © 2011 IEEE.

  15. Parameter Optimization of Information Channels for Laser Fluorescence Method of Vegetation Monitoring

    Directory of Open Access Journals (Sweden)

    M. L. Belov

    2015-01-01

    Full Text Available Nowadays, there is a growing interest in application of remote monitoring and accounting systems in agriculture.One of the promising areas of remote vegetation monitoring is a fluorescence analysis, as it potentially allows sensing stress of plants according to characteristics of their fluorescent radiation.The shape of the fluorescence spectra of vegetation in the normal condition differs from that of the fluorescence spectra of vegetation in stressful conditions. This potentially allows you to sence the plants by recording information about the shape of the fluorescence spectra.Analysis of the fluorescence spectrum shape can be replaced by the analysis of fluorescence intensities in several spectral bands, which simpifies problem-solving.Currently, there are various devices developed for laser fluorescence sensing of plant stress. However, a lot of issues important to the practice remain unclear.Most of these issues concern the parameters of receiving channels to record information signals, which allow you to perceve the stress-sensed plants:- how many information channels of spectral bands better to use;- what the best width of these spectral bands of information is ;- what is the best width of the spectral bands of information;- what the best threshold value for the threshold algorithm is, and if there is the better algorithm to process measurement data.The work uses mathematical modeling based on the experimentally measured fluorescence spectra to determine the optimal (in terms of probability of sensing characteristics of the stress of plants, i.e. the probability of good sense and false alarm parameters of information channels for laser fluorescence method to sense the plant stress: the central wavelength of the information spectral bands, their spectral width, and parameters of the algorithm in the case of processing two spectral channels of information. It is shown that using the additional third information spectral band allows you to

  16. Healthcare.gov State Marketplace Information

    Data.gov (United States)

    U.S. Department of Health & Human Services — Every state will have a Health Insurance Marketplace, but each state can choose how it will operate. States can create and run their own Marketplace, or have a...

  17. Continuous-variable quantum teleportation of even and odd coherent states through varied gain channels

    Institute of Scientific and Technical Information of China (English)

    Li Ying; Zhang Jing; Zhang Jun-Xiang; Zhang Tian-Cai

    2006-01-01

    This paper has investigated quantum teleportation of even and odd coherent states in terms of the EPR entanglement states for continuous variables. It discusses the relationship between the fidelity and the entanglement of EPR states, which is characterized by the degree of squeezing and the gain of classical channels. It shows that the quality of teleporting quantum states also depends on the characteristics of the states themselves. The properties of teleporting even and odd coherent states at different intensities are investigated. The difference of teleporting two such kinds of quantum states are analysed based on the quantum distance function.

  18. Hispanic women's preferences for breast health information: subjective cultural influences on source, message, and channel.

    Science.gov (United States)

    Oetzel, John; De Vargas, Felicia; Ginossar, Tamar; Sanchez, Christina

    2007-01-01

    The purpose of this study was to investigate the influence of 3 subjective cultural variables--self-construals (independence and interdependence), ethnic identity (bicultural, assimilation, traditional, and marginal), and cultural health attributions (equity and behavioral-environmental attributions)--on source, message, and channel preferences for receiving breast health information by Hispanic women age 35 or older. Subjective cultural variables collectively accounted for 2% to 28% of the variance in communication preferences. In addition, several associations were discovered: (a) having an interdependent self-construal was associated positively with preferences for significant other as a source, family sources, fear messages, media channels, and face-to-face channels; (b) having a bicultural identity was associated positively with preferences for family sources and media channels, but negatively with a desire for no information; and (c) having a marginal identity and equity attributions were associated positively with preferences for fear messages and a desire for no information, but negatively with preferences for expert sources. These findings are discussed in the context of tailoring breast health information to Hispanic women using computer technology and entertainment-education.

  19. In search of information: Investigating source and channel choices in business-to-government service interactions

    NARCIS (Netherlands)

    Boer, van den Yvon; Arendsen, Rex; Pieterson, Willem

    2016-01-01

    Businesses, far more frequently than citizens, need government information and services to exert their rights and duties. In optimizing their service delivery processes, governments tend to focus on a set of communication channels they offer to businesses to deliver these services. However, in reali

  20. Phosphorus transport and retention in a channel draining an urban, tropical catchment with informal settlements

    NARCIS (Netherlands)

    Nyenje, P.M.; Meijer, L.M.G.; Foppen, J.W.; Kulabako, R.; Uhlenbrook, S.

    2014-01-01

    rban catchments in sub-Saharan Africa (SSA) are increasingly becoming a major source of phosphorus (P) to downstream ecosystems. This is primarily due to large inputs of untreated wastewater to urban drainage channels, especially in informal settlements (or slums). However, the processes governing t

  1. Scheme for teleportation of unknown single qubit state via continuous variables entangling channel

    Institute of Scientific and Technical Information of China (English)

    Wang Zhong-Jie; Zhang Kan; Fan Chao-Yang

    2010-01-01

    A new scheme for quantum teleportation of single quantum bit state with using continuous variables entangling channel is presented. In our scheme two entangled light fields are employed. An outstanding characteristic of this scheme is that one atomic state is transmitted directly to another atom without using the third atom as the mediate.

  2. Quantum Entanglement Channel based on Excited States in a Spin Chain

    Institute of Scientific and Technical Information of China (English)

    张少良; 杜良辉; 郭光灿; 周幸祥; 周正威

    2011-01-01

    We study the possibility of using a spin chain to construct a quantum entanglement channel that can be used for quantum state transmission in a solid state system.We analyze the spin chain's states under various z-directional magnetic field and spin interactions to determine the entanglement between Alice and Bob's spins.We derive the conditions under which this entanglement can be distilled,and find that a spin chain of arbitrary length can be used as a quantum channel for quantum state transmission when the number of spin flips in the chain is large.%We study the possibility of using a spin chain to construct a quantum entanglement channel that can be used for quantum state transmission in a solid state system. We analyze the spin chain's states under various z-directional magnetic field and spin interactions to determine the entanglement between Alice and Bob's spins. We derive the conditions under which this entanglement can be distilled, and find that a spin chain of arbitrary length can be used as a quantum channel for quantum state transmission when the number of spin Hips in the chain is large.

  3. Use of the Internet for Health Information: United States, 2009

    Science.gov (United States)

    ... National Technical Information Service NCHS Use of the Internet for Health Information: United States, 2009 Recommend on ... more likely than men to have used the Internet for health information. Women were more likely than ...

  4. The Capacity of Finite-State Channels in the High-Noise Regime

    CERN Document Server

    Pfister, Henry D

    2010-01-01

    This paper considers the derivative of the entropy rate of a hidden Markov process with respect to the observation probabilities. The main result is a compact formula for the derivative that can be evaluated easily using Monte Carlo methods. It is applied to the problem of computing the capacity of a finite-state channel (FSC) and, in the high-noise regime, the formula has a simple closed-form expression that enables series expansion of the capacity of a FSC. This expansion is evaluated for a binary-symmetric channel under a (0,1) run-length limited constraint and an intersymbol-interference channel with Gaussian noise.

  5. Energy Efficient Spectrum Sensing for State Estimation over A Wireless Channel

    OpenAIRE

    Cao, Xianghui; Zhou, Xiangwei; Cheng, Yu

    2014-01-01

    The performance of remote estimation over wireless channel is strongly affected by sensor data losses due to interference. Although the impact of interference can be alleviated by performing spectrum sensing and then transmitting only when the channel is clear, the introduction of spectrum sensing also incurs extra energy expenditure. In this paper, we investigate the problem of energy efficient spectrum sensing for state estimation of a general linear dynamic system, and formulate an optimiz...

  6. Paranoid Secondary: Waterfilling in a Cognitive Interference Channel with Partial Information

    CERN Document Server

    Dash, Debashis

    2011-01-01

    We study a two-user cognitive channel, where the primary flow is sporadic, cannot be re-designed and operating below its link capacity. To study the impact of primary traffic uncertainty, we propose a block activity model that captures the random on-off periods of primary's transmissions. Each block in the model can be split into parallel Gaussian-mixture channels, such that each channel resembles a multiple user channel (MAC) from the point of view of the secondary user. The secondary senses the current state of the primary at the start of each block. We show that the optimal power transmitted depends on the sensed state and the optimal power profile is paranoid, i.e. either growing or decaying in power as a function of time. We show that such a scheme achieves capacity when there is no noise in the sensing. The optimal transmission for the secondary performs rate splitting and follows a layered water-filling power allocation for each parallel channel to achieve capacity. The secondary rate approaches a geni...

  7. 基于非理想信道状态信息的最小化均方误差非线性收发机设计%Minimum Mean Square Error Non-linear Transceiver Design Based on Imperfect Channel State Information

    Institute of Scientific and Technical Information of China (English)

    耿烜; 何迪

    2012-01-01

    A design method for nonlinear transceiver with Tomlinson-Harashima precoding(THP) struc ture was proposed based on minimum mean square error (MSE) criterion, when the transceiver knows the imperfect channel state information (CSI) for multiple-input multiple-output (MIMO) system. The MSE is derived firstly, and then transformed as the function of only one variable being precoding matrix. By minimizing the lower bound of MSE using optimization and matrix theory, the optimal precoding matrix and the closed-form of the lower bound are obtained, so that the total non-linear transceiver matrices are solved. The simulation results show that the proposed method outperforms the existing linear transceiver and the classic THP transceiver.%在多输入多输出系统中,当收发端已知非理想信道状态信息时,提出了一种基于最小化均方误差准则的非线性收发机设计方法,其结构基于汤姆林森一哈拉希玛预编码(THP).首先研究了收发信号的均方误差表达式,并将其转换为预编码矩阵的函数;然后,通过最优化及矩阵论方法最小化均方误差的下界,求解最优预编码矩阵以及下界的闭式解,进而获得整个非线性收发机矩阵.仿真结果表明,该方法性能优于现有的线性收发机设计和经典的THP收发机设计.

  8. Joint Source-Channel Decoding of Variable-Length Codes with Soft Information: A Survey

    Directory of Open Access Journals (Sweden)

    Siohan Pierre

    2005-01-01

    Full Text Available Multimedia transmission over time-varying wireless channels presents a number of challenges beyond existing capabilities conceived so far for third-generation networks. Efficient quality-of-service (QoS provisioning for multimedia on these channels may in particular require a loosening and a rethinking of the layer separation principle. In that context, joint source-channel decoding (JSCD strategies have gained attention as viable alternatives to separate decoding of source and channel codes. A statistical framework based on hidden Markov models (HMM capturing dependencies between the source and channel coding components sets the foundation for optimal design of techniques of joint decoding of source and channel codes. The problem has been largely addressed in the research community, by considering both fixed-length codes (FLC and variable-length source codes (VLC widely used in compression standards. Joint source-channel decoding of VLC raises specific difficulties due to the fact that the segmentation of the received bitstream into source symbols is random. This paper makes a survey of recent theoretical and practical advances in the area of JSCD with soft information of VLC-encoded sources. It first describes the main paths followed for designing efficient estimators for VLC-encoded sources, the key component of the JSCD iterative structure. It then presents the main issues involved in the application of the turbo principle to JSCD of VLC-encoded sources as well as the main approaches to source-controlled channel decoding. This survey terminates by performance illustrations with real image and video decoding systems.

  9. One-Way Information Deficit and Geometry for a Class of Two-Qubit States

    Institute of Scientific and Technical Information of China (English)

    WANG Yao-Kun; MA Teng; LI Bo; WANG Zhi-Xi

    2013-01-01

    The work deficit,as introduced by Jonathan Oppenheim et al.[Phys.Rev.Lett.89 (2002) 180402]is a good measure of the quantum correlations in a state and provides a new standpoint for understanding quantum non-locality.In this paper,we analytically evaluate the one-way information deficit (OWID) for the Bell-diagonal states and a class of two-qubit states and further give the geometry picture for OWID.The dynamic behavior of the OWID under decoherence channel is investigated and it is shown that the OWID of some classes of X states is more robust against the decoherence than the entanglement.

  10. Perfect controlled joint remote state preparation independent of entanglement degree of the quantum channel

    Energy Technology Data Exchange (ETDEWEB)

    An, Nguyen Ba, E-mail: nban@iop.vast.ac.vn; Bich, Cao Thi

    2014-11-14

    We construct a quantum circuit to produce a task-oriented partially entangled state and use it as the quantum channel for controlled joint remote state preparation. Unlike most previous works, where the parameters of the quantum channel are given to the receiver who can accomplish the task only probabilistically by consuming auxiliary resource, operation and measurement, here we give them to the supervisor. Thanks to the knowledge of the task-oriented quantum channel parameters, the supervisor can carry out proper complete projective measurement, which, combined with the feed-forward technique adapted by the preparers, not only much economizes (simplifies) the receiver's resource (operation) but also yields unit total success probability. Notably, such apparent perfection does not depend on the entanglement degree of the shared quantum channel. Our protocol is within the reach of current quantum technologies. - Highlights: • Controlled joint remote state preparation is considered. • Quantum circuit is proposed to produce task-oriented partially entangled channel. • The quantum channel parameter is given to the supervisor (not to the receiver). • Unit success probability without additional resource/operations/measurement. • Perfection is achieved regardless of the shared entanglement degree.

  11. Quantum information transmission in the quantum wireless multihop network based on Werner state

    Science.gov (United States)

    Shi, Li-Hui; Yu, Xu-Tao; Cai, Xiao-Fei; Gong, Yan-Xiao; Zhang, Zai-Chen

    2015-05-01

    Many previous studies about teleportation are based on pure state. Study of quantum channel as mixed state is more realistic but complicated as pure states degenerate into mixed states by interaction with environment, and the Werner state plays an important role in the study of the mixed state. In this paper, the quantum wireless multihop network is proposed and the information is transmitted hop by hop through teleportation. We deduce a specific expression of the recovered state not only after one-hop teleportation but also across multiple intermediate nodes based on Werner state in a quantum wireless multihop network. We also obtain the fidelity of multihop teleportation. Project supported by the Prospective Future Network Project of Jiangsu Province, China (Grant No. BY2013095-1-18) and the Independent Project of State Key Laboratory of Millimeter Waves (Grant No. Z201504).

  12. Exact performance of cooperative spectrum sensing for cognitive radios with quantized information under imperfect reporting channels

    KAUST Repository

    Ben Ghorbel, Mahdi

    2013-09-01

    Spectrum sensing is the first and main step for cognitive radio systems to achieve an efficient use of the spectrum. Cooperation among cognitive radio users is a technique employed to improve the sensing performance by exploiting the diversity between the sensing channels to overcome the fading and shadowing effects which allows reduction of miss-detection and false alarm probabilities. Information can be exchanged between cooperating users in different formats from the binary hard information to the full soft information. Quantized information has shown its efficiency as a trade-off between binary hard and full soft for other cooperative schemes, in this paper, we investigate the use of quantized information between cooperating cognitive users. We derive closed-form expressions of the cooperative average false alarm and detection probabilities over fading channels for a generalized system model with not necessarily identical average sensing Signal-to-Noise Ratio (SNR) and imperfect reporting channels. Numerical simulations allow us to conclude a tradeoff between the quantization size and the reporting energy in order to achieve the optimal cooperative error probability. Copyright © 2013 by the Institute of Electrical and Electronic Engineers, Inc.

  13. The Degrees of Freedom of the Compound MIMO Broadcast Channels with Finite States

    CERN Document Server

    Maddah-Ali, Mohammad Ali

    2009-01-01

    Multiple-antenna broadcast channels with $M$ transmit antennas and $K$ single-antenna receivers is considered, where the channel of receiver $r$ takes one of the $J_r$ finite values. It is assumed that the channel states of each receiver are randomly selected from $\\mathcal{R}^{M\\times 1}$. It is shown that no matter what $J_r$ is, the degrees of freedom (DoF) of $\\frac{MK}{M+K-1}$ is achievable. The achievable scheme relies on the idea of interference alignment at receivers, without exploiting the possibility of cooperation among transmit antennas. It is proven that if $J_r \\geq M$, $r=1,...,K$, this scheme achieves the optimal DoF. This results implies that when the uncertainty of the base station about the channel realization is considerable, the system loses the gain of cooperation. However, it still benefits from the gain of interference alignment. In fact, in this case, the compound broadcast channel is treated as a compound X channel. Moreover, it is shown that when the base station knows the channel s...

  14. Scheme for splitting quantum information via W states in cavity QED systems

    Institute of Scientific and Technical Information of China (English)

    Yu Xi-Mei; Gu Yong-Jian; Ma Li-Zhen; Zhou Bang-An

    2008-01-01

    Assisted by multipartite entanglement,Quantum information may be split so that the original qubit can be reconstructed if and only if the recipients cooperate.This paper proposes an experimentally feasible scheme for splitting quantum information via W-type entangled states in cavity QED systems,where three-level Rydberg atoms interact with nonresonant cavities.Since W-type states are used as the quantum channel and the cavities are only virtually excited,the scheme is easy to implement and robust against decoherence,and the dependence on the quality factor of the cavities is greatly reduced.

  15. Teleportation of n-Particle State via n Pairs of EPR Channels

    Institute of Scientific and Technical Information of China (English)

    CAO Min; ZHU Shi-Qun; FANG Jian-Xing

    2004-01-01

    The teleportation of an arbitrary n-particle state (n ≥ 1) is proposed if n pairs of identical EPR states are utilized as quantum channels. Independent Bell state measurements are performed for joint measurement. By using a special Latin square of order 2n(n ≥ 1), explicit expressions of outcomes after the Bell state measurements by Alice (sender) and the corresponding unitary transformations by Bob (receiver) can be derived. It is shown that the teleportation of n-particle state can be implemented by a series of single-qubit teleportation.

  16. Information guided channel hopping with an arbitrary number of transmit antennas

    KAUST Repository

    Yang, Yuli

    2012-10-01

    In order to realize the information guided channel hopping, also known as spatial modulation, with more design flexibility, in this paper we propose a novel scheme that allows operation with an arbitrary number of transmit antennas. Once the number of transmit antennas is not a power of two, the antennas\\' symbols are mapped by different numbers of bits. Subsequently, constellations with different orders are exploited for the modulation of radiated symbols so as to guarantee that the total number of bits transmitted at each time slot remains the same. Furthermore, we introduce a decoding algorithm with low complexity for this design. Numerical results on bit error rate performance are provided and substantiate that the proposed scheme turns out to be a promising alternative to the design of information guided channel hopping. © 2012 IEEE.

  17. FMRP regulates neurotransmitter release and synaptic information transmission by modulating action potential duration via BK channels.

    Science.gov (United States)

    Deng, Pan-Yue; Rotman, Ziv; Blundon, Jay A; Cho, Yongcheol; Cui, Jianmin; Cavalli, Valeria; Zakharenko, Stanislav S; Klyachko, Vitaly A

    2013-02-20

    Loss of FMRP causes fragile X syndrome (FXS), but the physiological functions of FMRP remain highly debatable. Here we show that FMRP regulates neurotransmitter release in CA3 pyramidal neurons by modulating action potential (AP) duration. Loss of FMRP leads to excessive AP broadening during repetitive activity, enhanced presynaptic calcium influx, and elevated neurotransmitter release. The AP broadening defects caused by FMRP loss have a cell-autonomous presynaptic origin and can be acutely rescued in postnatal neurons. These presynaptic actions of FMRP are translation independent and are mediated selectively by BK channels via interaction of FMRP with BK channel's regulatory β4 subunits. Information-theoretical analysis demonstrates that loss of these FMRP functions causes marked dysregulation of synaptic information transmission. FMRP-dependent AP broadening is not limited to the hippocampus, but also occurs in cortical pyramidal neurons. Our results thus suggest major translation-independent presynaptic functions of FMRP that may have important implications for understanding FXS neuropathology.

  18. Extracellular potassium inhibits Kv7.1 potassium channels by stabilizing an inactivated state

    DEFF Research Database (Denmark)

    Larsen, Anders Peter; Steffensen, Annette Buur; Grunnet, Morten;

    2011-01-01

    Kv7.1 (KCNQ1) channels are regulators of several physiological processes including vasodilatation, repolarization of cardiomyocytes, and control of secretory processes. A number of Kv7.1 pore mutants are sensitive to extracellular potassium. We hypothesized that extracellular potassium also...... modulates wild-type Kv7.1 channels. The Kv7.1 currents were measured in Xenopus laevis oocytes at different concentrations of extracellular potassium (1-50 mM). As extracellular potassium was elevated, Kv7.1 currents were reduced significantly more than expected from theoretical calculations based...... on the Goldman-Hodgkin-Katz flux equation. Potassium inhibited the steady-state current with an IC(50) of 6.0 ± 0.2 mM. Analysis of tail-currents showed that potassium increased the fraction of channels in the inactivated state. Similarly, the recovery from inactivation was slowed by potassium, suggesting...

  19. Assessing the Impact of Information Channels on the Understanding of Ground Truth

    Science.gov (United States)

    2012-06-01

    information, some of which may be relevant (Butcher, 1998). Klapp (1986) states that information presented at a rate too high for a receiver to...June 13–16. Klapp , O.E. (1986). In overload and boredom: Essays on the quality of life in the information society. Connecticut: Greenwood Press

  20. Information flow in agriculture – through new channels for improved effectiveness

    Directory of Open Access Journals (Sweden)

    Mihály Csótó

    2010-11-01

    Full Text Available Agriculture has undergone significant changes since the industrial revolution. The industrial age and the market economy have moulded agriculture in their image just as much as the characteristics and tools of the information age have recently been transforming its previous operation. Information and communication technology (ICTtake-up in agriculture remains low, and the reasons behind this barely changed in the last 20-30 years. Information technologies are regarded as mediating channels and a vehicle for new services. It is important to research the various aspects of adoption of newinformation technology, and also not only the use, but the “effective use” of it (Gurstein,2003. Information-intensive agriculture is fundamentally determined by information, knowledge and the decision-making farmers, in effect the human factor; therefore, studies aimed at the improvement of the situation of agriculture with ICT tools must be centred on the human element.

  1. Quantum information processing with mesoscopic photonic states

    DEFF Research Database (Denmark)

    Madsen, Lars Skovgaard

    2012-01-01

    The thesis is built up around a versatile optical experimental setup based on a laser, two optical parametric ampliers, a few sets of modulators and two sets of homodyne detectors, which together with passive linear optics generate, process and characterize various types of Gaussian quantum states....... Using this setup we have experimentally and theoretically investigated Gaussian quantum discord, continuous variable quantum key distribution and quantum polarization. The Gaussian discord broadens the definition of non-classical correlations from entanglement, to all types of correlations which cannot...... in the mixture of coherent states. Further we investigate the robustness of the discord of a broader range of states and suggest a toolbox of states which can be used to test if a protocol is discord based, before performing a rigid proof. Gaussian quantum key distribution can be implemented with current...

  2. Properties on the distant distribution of entanglement for arbitrary two-qubit pure states via noisy quantum channels

    Institute of Scientific and Technical Information of China (English)

    Wang Qiong; Li Ji-Xin; Zeng Hao-Sheng

    2009-01-01

    This paper investigates the change of entanglement for transmitting an arbitrarily entangled two-qubit pure state via one of three typical kinds of noisy quantum channels:amplitude damping quantum channel,phase damping quantum channel and depolarizing quantum channel.It finds,in all these three cases,that the output distant entanglement(measured by concurrence)reduces proportionately with respect to its initial amount,and the decaying ratio is determined only by the noisy characteristics of quantum channels and independent of the form of initial input state.

  3. Disseminating Library and Information Science Research in the United States

    Science.gov (United States)

    Ferguson, Douglas

    1975-01-01

    A descriptive survey of the organizations and institutions which conduct and support current research in library and information science in the United States of America and of the major sources of research information. (Author)

  4. Delay-Sensitive Distributed Power and Transmission Threshold Control for S-ALOHA Network with Finite State Markov Fading Channels

    CERN Document Server

    Huang, Huang

    2009-01-01

    In this paper, we consider the delay-sensitive power and transmission threshold control design in S-ALOHA network with FSMC fading channels. The random access system consists of an access point with K competing users, each has access to the local channel state information (CSI) and queue state information (QSI) as well as the common feedback (ACK/NAK/Collision) from the access point. We seek to derive the delay-optimal control policy (composed of threshold and power control). The optimization problem belongs to the memoryless policy K-agent infinite horizon decentralized Markov decision process (DEC-MDP), and finding the optimal policy is shown to be computationally intractable. To obtain a feasible and low complexity solution, we recast the optimization problem into two subproblems, namely the power control and the threshold control problem. For a given threshold control policy, the power control problem is decomposed into a reduced state MDP for single user so that the overall complexity is O(NJ), where N a...

  5. 1020MHz single-channel proton fast magic angle spinning solid-state NMR spectroscopy.

    Science.gov (United States)

    Pandey, Manoj Kumar; Zhang, Rongchun; Hashi, Kenjiro; Ohki, Shinobu; Nishijima, Gen; Matsumoto, Shinji; Noguchi, Takashi; Deguchi, Kenzo; Goto, Atsushi; Shimizu, Tadashi; Maeda, Hideaki; Takahashi, Masato; Yanagisawa, Yoshinori; Yamazaki, Toshio; Iguchi, Seiya; Tanaka, Ryoji; Nemoto, Takahiro; Miyamoto, Tetsuo; Suematsu, Hiroto; Saito, Kazuyoshi; Miki, Takashi; Ramamoorthy, Ayyalusamy; Nishiyama, Yusuke

    2015-12-01

    This study reports a first successful demonstration of a single channel proton 3D and 2D high-throughput ultrafast magic angle spinning (MAS) solid-state NMR techniques in an ultra-high magnetic field (1020MHz) NMR spectrometer comprised of HTS/LTS magnet. High spectral resolution is well demonstrated.

  6. Evolution of a Thermo Vacuum State in a Single-Mode Amplitude Dissipative Channel

    Institute of Scientific and Technical Information of China (English)

    WANG Chang-Chun; FAN Hong-Yi

    2010-01-01

    @@ We investigate how an initial thermo vacuum state, in the context of thermo field dynamics, evolves in a single-mode amplitude dissipative channel, and find that in this process the thermo squeezing effect decreases while the fictitious-mode vacuum becomes chaotic.

  7. Entangled States Used in Remote Information Concentration and Their Properties

    Institute of Scientific and Technical Information of China (English)

    CHEN Yin-Hua; YU Ya-Fei; ZHANG Zhi-Ming

    2006-01-01

    We analyse a process of remote information concentration achieved by the W state. The result turns out to be neither as good as performed by the GHZ state nor as by the Smolin bound entangled state. Based on this particular phenomenon, the properties of the three entangled states are realized.

  8. 32 CFR Appendix C to Part 86 - State Information

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false State Information C Appendix C to Part 86 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL, MILITARY AND CIVILIAN... State Office Building, Des Moines, IA 50319 6 Release within State, COMM: 515-281-5138. State of...

  9. Cognitive two-way relay beamforming: Design with resilience to channel state uncertainties

    KAUST Repository

    Ubaidulla, P.

    2016-07-26

    In this paper, we propose a robust distributed relay beamformer design for cognitive radio network operating under uncertainties in the available channel state information. The cognitive network consists of a pair of transceivers and a set of non-regenerative two-way relays that assist the communication between the transceiver pair. The secondary nodes share the spectrum with a licensed primary user node while ensuring that the interference to the primary receiver is maintained below a certain threshold. The proposed robust design maximizes the worst-case signal-to-interference-plus-noise ratio at the secondary transceivers while satisfying constraints on the interference to the primary user and on the total relay transmit power. Though the robust design problem is not a convex problem in its original form, we show that it can be reformulated as a convex optimization problem, which can be solved efficiently. Numerical results are provided and illustrate the merits of the proposed design for various operating conditions and parameters. © 2016 IEEE.

  10. Intercept-resend attack on six-state quantum key distribution over collective-rotation noise channels

    Science.gov (United States)

    Kevin, Garapo; Mhlambululi, Mafu; Francesco, Petruccione

    2016-07-01

    We investigate the effect of collective-rotation noise on the security of the six-state quantum key distribution. We study the case where the eavesdropper, Eve, performs an intercept-resend attack on the quantum communication between Alice, the sender, and Bob, the receiver. We first derive the collective-rotation noise model for the six-state protocol and then parameterize the mutual information between Alice and Eve. We then derive quantum bit error rate for three intercept-resend attack scenarios. We observe that the six-state protocol is robust against intercept-resend attacks on collective rotation noise channels when the rotation angle is kept within certain bounds. Project supported by the South African Research Chair Initiative of the Department of Science and Technology and National Research Foundation.

  11. Intercept-resend attack on six-state quantum key distribution over collective-rotation noise channels

    Institute of Scientific and Technical Information of China (English)

    Kevin Garapo; Mhlambululi Mafu; Francesco Petruccione

    2016-01-01

    We investigate the effect of collective-rotation noise on the security of the six-state quantum key distribution. We study the case where the eavesdropper, Eve, performs an intercept-resend attack on the quantum communication between Alice, the sender, and Bob, the receiver. We first derive the collective-rotation noise model for the six-state protocol and then parameterize the mutual information between Alice and Eve. We then derive quantum bit error rate for three intercept-resend attack scenarios. We observe that the six-state protocol is robust against intercept-resend attacks on collective rotation noise channels when the rotation angle is kept within certain bounds.

  12. Passive states as optimal inputs for single-jump lossy quantum channels

    Science.gov (United States)

    De Palma, Giacomo; Mari, Andrea; Lloyd, Seth; Giovannetti, Vittorio

    2016-06-01

    The passive states of a quantum system minimize the average energy among all the states with a given spectrum. We prove that passive states are the optimal inputs of single-jump lossy quantum channels. These channels arise from a weak interaction of the quantum system of interest with a large Markovian bath in its ground state, such that the interaction Hamiltonian couples only consecutive energy eigenstates of the system. We prove that the output generated by any input state ρ majorizes the output generated by the passive input state ρ0 with the same spectrum of ρ . Then, the output generated by ρ can be obtained applying a random unitary operation to the output generated by ρ0. This is an extension of De Palma et al. [IEEE Trans. Inf. Theory 62, 2895 (2016)], 10.1109/TIT.2016.2547426, where the same result is proved for one-mode bosonic Gaussian channels. We also prove that for finite temperature this optimality property can fail already in a two-level system, where the best input is a coherent superposition of the two energy eigenstates.

  13. Tight bound on coherent-state-based entanglement generation over lossy channels

    CERN Document Server

    Azuma, Koji; Koashi, Masato; Imoto, Nobuyuki

    2009-01-01

    The first stage of the hybrid quantum repeaters is entanglement generation based on transmission of pulses in coherent states over a lossy channel. Protocols to make entanglement with only one type of error are favorable for rendering subsequent entanglement distillation efficient. Here we provide the tight upper bound on performances of these protocols that is determined only by the channel loss. In addition, we show that this bound is achievable by utilizing a proposed protocol [arXiv:0811.3100] composed of a simple combination of linear optical elements and photon-number-resolving detectors.

  14. Adaptive Channel Estimation based on Soft Information Processing in Broadband Spatial Multiplexing Receivers

    Directory of Open Access Journals (Sweden)

    P. Beinschob

    2010-11-01

    Full Text Available In this paper we present a novel approach in Multiple-Input Multiple Output (MIMO Orthogonal Frequency Division Multiplexing (OFDM channel estimation technique based on a Decision Directed Recursive Least Squares (RLS algorithm in which no pilot symbols need to be integrated in the data after a short initial preamble. The novelty and key concept of the proposed technique is the block-wise causal and anti-causal RLS processing that yields two independent processings of RLS along with the associated decisions. Due to the usage of low density parity check (LDPC channel code, the receiver operates with soft information, which enables us to introduce a new modification of the Turbo principle as well as a simple information combining approach based on approximated aposteriori log-likelihood ratios (LLRs. Although the computational complexity is increased by both of our approaches, the latter is relatively less complex than the former. Simulation results show that these implementations outperform the simple RLS-DDCE algorithm and yield lower bit error rates (BER and more accurate channel estimates.

  15. KATP channel as well as SGLT1 participates in GIP secretion in the diabetic state.

    Science.gov (United States)

    Ogata, Hidetada; Seino, Yusuke; Harada, Norio; Iida, Atsushi; Suzuki, Kazuyo; Izumoto, Takako; Ishikawa, Kota; Uenishi, Eita; Ozaki, Nobuaki; Hayashi, Yoshitaka; Miki, Takashi; Inagaki, Nobuya; Tsunekawa, Shin; Hamada, Yoji; Seino, Susumu; Oiso, Yutaka

    2014-08-01

    Glucose-dependent insulinotropic polypeptide (GIP), a gut hormone secreted from intestinal K-cells, potentiates insulin secretion. Both K-cells and pancreatic β-cells are glucose-responsive and equipped with a similar glucose-sensing apparatus that includes glucokinase and an ATP-sensitive K(+) (KATP) channel comprising KIR6.2 and sulfonylurea receptor 1. In absorptive epithelial cells and enteroendocrine cells, sodium glucose co-transporter 1 (SGLT1) is also known to play an important role in glucose absorption and glucose-induced incretin secretion. However, the glucose-sensing mechanism in K-cells is not fully understood. In this study, we examined the involvement of SGLT1 (SLC5A1) and the KATP channels in glucose sensing in GIP secretion in both normal and streptozotocin-induced diabetic mice. Glimepiride, a sulfonylurea, did not induce GIP secretion and pretreatment with diazoxide, a KATP channel activator, did not affect glucose-induced GIP secretion in the normal state. In mice lacking KATP channels (Kir6.2(-/-) mice), glucose-induced GIP secretion was enhanced compared with control (Kir6.2(+) (/) (+)) mice, but was completely blocked by the SGLT1 inhibitor phlorizin. In Kir6.2(-/-) mice, intestinal glucose absorption through SGLT1 was enhanced compared with that in Kir6.2(+) (/) (+) mice. On the other hand, glucose-induced GIP secretion was enhanced in the diabetic state in Kir6.2(+) (/) (+) mice. This GIP secretion was partially blocked by phlorizin, but was completely blocked by pretreatment with diazoxide in addition to phlorizin administration. These results demonstrate that glucose-induced GIP secretion depends primarily on SGLT1 in the normal state, whereas the KATP channel as well as SGLT1 is involved in GIP secretion in the diabetic state in vivo.

  16. USER-ORIENTED INFORMATION SYSTEMS FOR STATE AND LOCAL GOVERNMENT

    Science.gov (United States)

    Potential state and local government users of information systems are classified in terms of categories of activities and levels of organizational...situation in state and local government information systems is then described, indicating a need for more advanced, user-oriented techniques. Such methods and

  17. Information-Theoretic Analysis of Underwater Acoustic OFDM Systems in Highly Dispersive Channels

    Directory of Open Access Journals (Sweden)

    Francois-Xavier Socheleau

    2012-01-01

    established by the ISI/ICI and are based on lower bounds on mutual information that assume independent and identically distributed input data symbols. In agreement with recent statistical analyses of experimental shallow-water data, the channel is modeled as a multivariate Rician fading process with a slowly time-varying mean and with potentially correlated scatterers, which is more general than the common wide-sense stationary uncorrelated scattering model. Numerical assessments on real UA channels with spread factors around 10−1 show that reliable OFDM transmissions at 2 to 4 bits/sec/Hz are achievable provided an average signal-to-noise ratio of 15 to 20 dB.

  18. Information theory and statistical nuclear reactions. I. General theory and applications to few-channel problems

    Energy Technology Data Exchange (ETDEWEB)

    Mello, P.A.; Pereyra, P.; Seligman, T.H.

    1985-05-01

    Ensembles of scattering S-matrices have been used in the past to describe the statistical fluctuations exhibited by many nuclear-reaction cross sections as a function of energy. In recent years, there have been attempts to construct these ensembles explicitly in terms of S, by directly proposinng a statistical law for S. In the present paper, it is shown that, for an arbitrary number of channels, one can incorporate, in the ensemble of S-matrices, the conditions of flux conservation, time-reversal invariance, causality, ergodicity, and the requirement that the ensemble average coincide with the optical scattering matrix. Since these conditions do not specify the ensemble uniquely, the ensemble that has maximum information-entropy is dealt with among those that satisfy the above requirements. Some applications to few-channel problems and comparisons to Monte-Carlo calculations are presented.

  19. Redundant imprinting of information in non-ideal environments: Quantum Darwinism via a noisy channel

    Science.gov (United States)

    Zwolak, Michael; Quan, Haitao; Zurek, Wojciech

    2011-03-01

    Quantum Darwinism provides an information-theoretic framework for the emergence of the classical world from the quantum substrate. It recognizes that we - the observers - acquire our information about the ``systems of interest'' indirectly from their imprints on the environment. Objectivity, a key property of the classical world, arises via the proliferation of redundant information into the environment where many observers can then intercept it and independently determine the state of the system. While causing a system to decohere, environments that remain nearly invariant under the Hamiltonian dynamics, such as very mixed states, have a diminished ability to transmit information about the system, yet can still acquire redundant information about the system [1,2]. Our results show that Quantum Darwinism is robust with respect to non-ideal initial states of the environment. This research is supported by the U.S. Department of Energy through the LANL/LDRD Program.

  20. Redundant imprinting of information in nonideal environments: Objective reality via a noisy channel

    Science.gov (United States)

    Zwolak, Michael; Quan, H. T.; Zurek, Wojciech H.

    2010-06-01

    Quantum Darwinism provides an information-theoretic framework for the emergence of the objective, classical world from the quantum substrate. The key to this emergence is the proliferation of redundant information throughout the environment where observers can then intercept it. We study this process for a purely decohering interaction when the environment, E, is in a nonideal (e.g., mixed) initial state. In the case of good decoherence, that is, after the pointer states have been unambiguously selected, the mutual information between the system, S, and an environment fragment, F, is given solely by F’s entropy increase. This demonstrates that the environment’s capacity for recording the state of S is directly related to its ability to increase its entropy. Environments that remain nearly invariant under the interaction with S, either because they have a large initial entropy or a misaligned initial state, therefore have a diminished ability to acquire information. To elucidate the concept of good decoherence, we show that, when decoherence is not complete, the deviation of the mutual information from F’s entropy change is quantified by the quantum discord, i.e., the excess mutual information between S and F is information regarding the initial coherence between pointer states of S. In addition to illustrating these results with a single-qubit system interacting with a multiqubit environment, we find scaling relations for the redundancy of information acquired by the environment that display a universal behavior independent of the initial state of S. Our results demonstrate that Quantum Darwinism is robust with respect to nonideal initial states of the environment: the environment almost always acquires redundant information about the system but its rate of acquisition can be reduced.

  1. Controlled Remote Preparation of a Two-Qubit State via an Asymmetric Quantum Channel

    Institute of Scientific and Technical Information of China (English)

    WANG Zhang-Yin

    2011-01-01

    I present a new scheme for probabilistic remote preparation of a general two-qubit state from a sender to either of two receivers.The quantum channel is composed of a partial entangled tripartite Greenberger-Horne-Zeilinger (GHZ) state and a W-type state.I try to realize the remote two-qubit preparation by using the usual projective measurement and the method of positive operator-valued measure, respectively.The corresponding success probabilities of the scheme with different methods as well as the total classical communication cost required in this scheme are also calculated.

  2. Electric field modulation of the membrane potential in solid-state ion channels.

    Science.gov (United States)

    Guan, Weihua; Reed, Mark A

    2012-12-12

    Biological ion channels are molecular devices that allow a rapid flow of ions across the cell membrane. Normal physiological functions, such as generating action potentials for cell-to-cell communication, are highly dependent on ion channels that can open and close in response to external stimuli for regulating ion permeation. Mimicking these biological functions using synthetic structures is a rapidly progressing yet challenging area. Here we report the electric field modulation of the membrane potential phenomena in mechanically and chemically robust solid-state ion channels, an abiotic analogue to the voltage-gated ion channels in living systems. To understand the complex physicochemical processes in the electric field regulated membrane potential behavior, both quasi-static and transient characteristics of converting transmembrane ion gradients into electric potential are investigated. It is found that the transmembrane potential can be adequately tuned by an external electrical stimulation, thanks to the unique properties of the voltage-regulated selective ion transport through a nanoscale channel.

  3. Purity of Gaussian states: measurement schemes and time-evolution in noisy channels

    CERN Document Server

    Paris, M A G; Serafini, A; De Siena, S

    2003-01-01

    We present a systematic study of the purity for Gaussian states of single-mode continuous variable systems. We prove the connection of purity to observable quantities for these states, and show that the joint measurement of two conjugate quadratures is necessary and sufficient to determine the purity at any time. The statistical reliability and the range of applicability of the proposed measurement scheme is tested by means of Monte Carlo simulated experiments. We then consider the dynamics of purity in noisy channels. We derive an evolution equation for the purity of general Gaussian states both in thermal and squeezed thermal baths. We show that purity is maximized at any given time for an initial coherent state evolving in a thermal bath, or for an initial squeezed state evolving in a squeezed thermal bath whose asymptotic squeezing is orthogonal to that of the input state.

  4. Maryland State information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-31

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Handbook Series Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the State of Maryland. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; and the full text of relevant statutes and regulations.

  5. Iowa state information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-02-09

    This volume is one of a series produced under contract with the DOE, By Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the state of Iowa. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; the full test of relevant statutes and regulations.

  6. California state information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-02-09

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the state of California. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; the full text of relevant statutes and regulations.

  7. Oregon state information handbook formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-31

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administater, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the State of Oregon. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; and the full text of relevant statutes and regulations.

  8. Pennsylvania state information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-31

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and State levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the State of Pennsylvania. It contains a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; and the full text of relevant statutes and regulations.

  9. Oregon state information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-31

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the State of Oregon. It contains a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; and the full text of relevant statutes and regulations.

  10. Ohio state information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    1981-02-09

    This volume is one of a series produced under contract with the DOE, by POLITECH CORPORATION to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the state of Ohio. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; the full test of relevant statutes and regulations.

  11. Florida state information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-02-27

    This volume is one of a series produced under contract with DOE, Office of Nuclear Waste Management, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the federal and state levels, the pertinent programs they administer, each affected state legislature, and current federal and state legislative and regulatory initiatives. This volume is a compilation of information about the State of Florida. It contains a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; and the full text of relevant statutes and regulations.

  12. Massachusetts state information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-02-09

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the state of Massachusetts. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; the full text of relevant statutes and regulations.

  13. Quantum secure direct communication with Greenberger-Horne-Zeilinger-type state (GHZ state) over noisy channels

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiao-Long; Zhang Yue-Xia; Wei Hua

    2009-01-01

    We propose a quantum error-rejection scheme for direct communication with three-qubit quantum codes based on the direct communication of secret messages without any secret key shared in advance. Given the symmetric and independent errors of the transmitted qubits, our scheme can tolerate a bit of error rate up to 33.1%, thus the protocol is deterministically secure against any eavesdropping attack even in a noisy channel.

  14. MPSK Symbol-based Soft-Information-Forwarding Scheme in Rayleigh Fading Channels

    Directory of Open Access Journals (Sweden)

    Huamei Xin

    2014-06-01

    Full Text Available In this paper, we proposed a symbol-based multiple phase shift keying (MPSK soft-information-forwarding (SIF scheme for a two-hop parallel relay wireless network in Rayleigh fading channel. First the binary information streams at the source are mapped into MPSK symbols, and the relays construct the relay processing function by passing the intermediate soft decisions. Then the relays broadcast the processed symbols to the destination. After the maximum ratio combination, the received symbols at the destination can be decided by maximum-likelihood (ML decision. Four MPSK symbol-based forwarding schemes are investigated and the simulation results show that the bit error rate (BER performance of soft information forwarding scheme has better BER performance than the existing memoryless forwarding scheme based on MPSK modulation, and it is more practical than the SIF scheme based on BPSK modulation

  15. Probabilistic Remote Preparation of a Three-Particle Entangled State via Two Different Non-maximally Entangled Channels

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We present two schemes for preparing remotely a three-particle entangled state by two different quantum channels. In the first scheme, two partial three-particle entangled states are used as the quantum channels, while in the second scheme, three two-particle non-maximally entangled states are employed as the quantum channels. It is shown that the remote state preparation can be successfully realized with certain probability, for both two schemes, if a sender performs some projective measurements and a receiver adopts some appropriate unitary transformations. It is shown also that the successful probabilities of these two schemes are different.

  16. Channelling information flows: a young researcher’s approach to knowledge management

    Directory of Open Access Journals (Sweden)

    Guilhem Chalancon

    2014-07-01

    Full Text Available As the volume of scientific literature continues to grow at an impressive pace, so too does the diversity of tools and approaches that are being proposed to track this knowledge. In the midst of such a vast ecosystem of journals and software, identifying meaningful innovation, as well as continuing to innovate, is essential to the emergence of powerful, flexible and easy-to-use ‘channels’ which researchers need to navigate the current scientific literature. In this article, the author uses the example of his own information consumption habits to suggest what he sees as the key components of such channels.

  17. Several teleportation schemes of an arbitrary unknown multi-particle state via different quantum channels

    Institute of Scientific and Technical Information of China (English)

    Peng Jia-Yin; Mo Zhi-Wen

    2013-01-01

    We first provide four new schemes for two-party quantum teleportation of an arbitrary unknown multi-particle state by using three-,four-,and five-particle states as the quantum channel,respectively.The successful probability and fidelity of the four schemes reach 1.In the first two schemes,the receiver can only apply one of the unitary transformations to reconstruct the original state,making it easier for these two schemes to be directly realized.In the third and fourth schemes,the sender can preform Bell-state measurements instead of multipartite entanglement measurements of the existing similar schemes,which makes real experiments more suitable.It is found that the last three schemes may become tripartite controlled teleportation schemes of teleporting an arbitrary multi-particle state after a simple modification.Finally,we present a new scheme for three-party sharing an arbitrary unknown multi-particle state.In this scheme,the sender first shares three three-particle GHZ states with two agents.After setting up the secure quantum channel,an arbitrary unknown multi-particle state can be perfectly teleported if the sender performs three Bell-state measurements,and either of two receivers operates an appropriate unitary transformation to obtain the original state with the help of other receiver's three single-particle measurements.The successful probability and fidelity of this scheme also reach 1.It is demonstrated that this scheme can be generalized easily to the case of sharing an arbitrary unknown multi-particle state among several agents.

  18. On the identification of sensory information from mixed nerves by using single-channel cuff electrodes

    Directory of Open Access Journals (Sweden)

    Udina Esther

    2010-04-01

    Full Text Available Abstract Background Several groups have shown that the performance of motor neuroprostheses can be significantly improved by detecting specific sensory events related to the ongoing motor task (e.g., the slippage of an object during grasping. Algorithms have been developed to achieve this goal by processing electroneurographic (ENG afferent signals recorded by using single-channel cuff electrodes. However, no efforts have been made so far to understand the number and type of detectable sensory events that can be differentiated from whole nerve recordings using this approach. Methods To this aim, ENG afferent signals, evoked by different sensory stimuli were recorded using single-channel cuff electrodes placed around the sciatic nerve of anesthetized rats. The ENG signals were digitally processed and several features were extracted and used as inputs for the classification. The work was performed on integral datasets, without eliminating any noisy parts, in order to be as close as possible to real application. Results The results obtained showed that single-channel cuff electrodes are able to provide information on two to three different afferent (proprioceptive, mechanical and nociceptive stimuli, with reasonably good discrimination ability. The classification performances are affected by the SNR of the signal, which in turn is related to the diameter of the fibers encoding a particular type of neurophysiological stimulus. Conclusions Our findings indicate that signals of acceptable SNR and corresponding to different physiological modalities (e.g. mediated by different types of nerve fibers may be distinguished.

  19. Understanding Farmers Information Network Implication For Effective Extension Delivery In Akwa Ibom State

    Directory of Open Access Journals (Sweden)

    Odoemelam

    2015-01-01

    Full Text Available ABSTRACT Appropriateness of information is a critical factor needed to stimulate the right knowledge and attitude of farmers towards sustainable transformation of agriculture. The study investigated the information network that exists among rural communities in Akwa-Ibom States and its implication for effective extension delivery. Even though AKADEPAkwa-Ibom State Agricultural Development Programmes are highly involved in the dissemination process it is important to analyze the information networks of the farmers to improve exchange of information with the following specific objectives identify the different wealth groups in the study area ascertain the information networks that exists in the area analyze the different information types and assess the strength and weakness of the information sources. Data were generated through Focus Group Discussion and Participatory Observation employing different methodologies like wealth ranking information diagram and linkage matrix analysis using Likerts scale type. Data generated were analyzed with simple descriptive statistics and means. Major results show that in wealth ranking two groups of respondents were identified the female households with mean score between 1.9 and male headed household with mean score of 2.00 2.99. on information network farmer to farmer with 21 market 14 church 15 were highest source of their information network. On perceived weakness and strength of the information network the information quality frequency of use timeliness of information flow and link up of information were adequate while reliability of information was not adequate. The results show that intra community information flow was suitable and accessible to rich farmers while inaccessible and often irrelevant to poor farmers. Therefore in the face of threat to food insecurity prevalent in the country it is important to put in place a platform that will afford farmers to ask questions and get substantive responses

  20. Information resources in state regulatory agencies-a California perspective

    Energy Technology Data Exchange (ETDEWEB)

    DiZio, S.M. [California Environmental Protection Agency, Sacramento (United States)

    1990-12-31

    Various state regulatory agencies have expressed a need for networking with information gatherers/researchers to produce a concise compilation of primary information so that the basis for regulatory standards can be scientifically referenced. California has instituted several programs to retrieve primary information, generate primary information through research, and generate unique regulatory standards by integrating the primary literature and the products of research. This paper describes these programs.

  1. Lidocaine stabilizes the open state of CNS voltage-dependent sodium channels.

    Science.gov (United States)

    Castañeda-Castellanos, David R; Nikonorov, Igor; Kallen, Roland G; Recio-Pinto, E

    2002-03-28

    We have previously reported that the lidocaine action is different between CNS and muscle batrachotoxin-modified Na+ channels [Salazar et al., J. Gen. Physiol. 107 (1996) 743-754; Brain Res. 699 (1995) 305-314]. In this study we examined lidocaine action on CNS Na+ currents, to investigate the mechanism of lidocaine action on this channel isoform and to compare it with that proposed for muscle Na+ currents. Na+ currents were measured with the whole cell voltage clamp configuration in stably transfected cells expressing the brain alpha-subunit (type IIA) by itself (alpha-brain) or together with the brain beta(1)-subunit (alphabeta(1)-brain), or the cardiac alpha-subunit (hH1) (alpha-cardiac). Lidocaine (100 microM) produced comparable levels of Na+ current block at positive potentials and of hyperpolarizing shift of the steady-state inactivation curve in alpha-brain and alphabeta(1)-brain Na+ currents. Lidocaine accelerated the rates of activation and inactivation, produced an hyperpolarizing shift in the steady-state activation curve and increased the current magnitude at negative potentials in alpha-brain but not in alphabeta(1)-brain Na+ currents. The lidocaine action in alphabeta(1)-brain resembled that observed in alpha-cardiac Na+ currents. The lidocaine-induced increase in current magnitude at negative potentials and the hyperpolarizing shift in the steady-state activation curve of alpha-brain, are novel effects and suggest that lidocaine treatment does not always lead to current reduction/block when it interacts with Na+ channels. The data are explained by using a modified version of the model proposed by Vedantham and Cannon [J. Gen. Physiol., 113 (1999) 7-16] in which we postulate that the difference in lidocaine action between alpha-brain and alphabeta(1)-brain Na+ currents could be explained by differences in the lidocaine action on the open channel state.

  2. Dirac Coupled Channel Analyses of the high-lying excited states at $^{22}$Ne(p,p$'$)$^{22}$Ne

    CERN Document Server

    Shim, Sugie

    2015-01-01

    Dirac phenomenological coupled channel analyses are performed using an optical potential model for the high-lying excited vibrational states at 800 MeV unpolarized proton inelastic scatterings from $^{22}$Ne nucleus. Lorentz-covariant scalar and time-like vector potentials are used as direct optical potentials and the first-order vibrational collective model is used for the transition optical potentials to describe the high-lying excited vibrational collective states. The complicated Dirac coupled channel equations are solved phenomenologically using a sequential iteration method by varying the optical potential and the deformation parameters. Relativistic Dirac coupled channel calculations are able to describe the high-lying excited states of the vibrational bands in $^{22}$Ne clearly better than the nonrelativistic coupled channel calculations. The channel-coupling effects of the multistep process for the excited states of the vibrational bands are investigated. The deformation parameters obtained from the ...

  3. Study on target characteristic polarization state in co-polarized channel for the coherent case

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The target characteristic polarization state in the co-polarized channel for the coherent case was studied in greater detail, with emphasis on the analysis of the characteristic polarization states variable with the target parameters. The Sinclair backscatter matrix was diagonalized under the change of polariza- tion basis via a unitary transformation matrix. Then the diagonal matrix was parameterized by four parameters viz. matrix amplitude, absolute phase, amplitude ratio and phase difference. The behavior of the characteristic polarization states with the varieties of target parameters was discussed together with the power density plot. The characteristic polarization states were displayed on the Poincare sphere and six conclusions were obtained, which provide theoretic support for decreasing the computational complexity of target characteristic polarization state, or anticipating its position in the power density plot. Several simple target cases were considered for validating these conclusions.

  4. Study on target characteristic polarization state in co-polarized channel for the coherent case

    Institute of Scientific and Technical Information of China (English)

    CHEN Qiang; GAO Gui; ZHOU XiaoGuang; JIANG YongMei; KUANG GangYao

    2009-01-01

    The target characteristic polarization state in the co-polarized channel for the coherent case was studied in greater detail,with emphasis on the analysis of the characteristic polarization states variable with the target parameters.The Sinclair backscatter matrix was diagonalized under the change of polarization basis via a unitary transformation matrix.Then the diagonal matrix was parameterized by four parameters viz.matrix amplitude,absolute phase,amplitude ratio and phase difference.The behavior of the characteristic polarization states with the varieties of target parameters was discussed together with the power density plot.The characteristic polarization states were displayed on the Poincare sphere and six conclusions were obtained,which provide theoretic support for decreasing the computational complexity of target characteristic polarization state,or anticipating its position in the power density plot.Several simple target cases were considered for validating these conclusions.

  5. ClC-1 chloride channels: state-of-the-art research and future challenges

    Directory of Open Access Journals (Sweden)

    Paola eImbrici

    2015-04-01

    Full Text Available The voltage-dependent ClC-1 chloride channel belongs to the CLC channel/transporter family. It is a homodimer comprising two individual pores which can operate independently or simultaneously according to two gating modes, the fast and the slow gate of the channel. ClC-1 is preferentially expressed in the skeletal muscle fibers where the presence of an efficient Cl- homeostasis is crucial for the correct membrane repolarization and propagation of action potential. As a consequence, mutations in the CLCN1 gene cause dominant and recessive forms of Myotonia Congenita, a rare skeletal muscle channelopathy caused by abnormal membrane excitation, and clinically characterized by muscle stiffness and various degrees of transitory weakness. Elucidation of the mechanistic link between the genetic defects and the disease pathogenesis is still incomplete and, at this time, there is no specific treatment for Myotonia Congenita. Still controversial is the subcellular localization pattern of ClC-1 channels in skeletal muscle as well as its modulation by some intracellular factors. The expression of ClC-1 in other tissues such as in brain and heart and the possible assembly of ClC-1/ClC-2 heterodimers further expand the physiological properties of ClC-1 and its involvement in diseases. A recent de novo CLCN1 truncation mutation in a patient with generalized epilepsy indeed postulates an unexpected role of this channel in the control of neuronal network excitability. This review summarizes the most relevant and state-of-the-art research on ClC-1 chloride channels physiology and associated diseases.

  6. Quantum information storage and state transfer based on spin systems

    CERN Document Server

    Song, Z

    2004-01-01

    The idea of quantum state storage is generalized to describe the coherent transfer of quantum information through a coherent data bus. In this universal framework, we comprehensively review our recent systematical investigations to explore the possibility of implementing the physical processes of quantum information storage and state transfer by using quantum spin systems, which may be an isotropic antiferromagnetic spin ladder system or a ferromagnetic Heisenberg spin chain. Our studies emphasize the physical mechanisms and the fundamental problems behind the various protocols for the storage and transfer of quantum information in solid state systems.

  7. Passing crisis and emergency risk communications: the effects of communication channel, information type, and repetition.

    Science.gov (United States)

    Edworthy, Judy; Hellier, Elizabeth; Newbold, Lex; Titchener, Kirsteen

    2015-05-01

    Three experiments explore several factors which influence information transmission when warning messages are passed from person to person. In Experiment 1, messages were passed down chains of participants using five different modes of communication. Written communication channels resulted in more accurate message transmission than verbal. In addition, some elements of the message endured further down the chain than others. Experiment 2 largely replicated these effects and also demonstrated that simple repetition of a message eliminated differences between written and spoken communication. In a final field experiment, chains of participants passed information however they wanted to, with the proviso that half of the chains could not use telephones. Here, the lack of ability to use a telephone did not affect accuracy, but did slow down the speed of transmission from the recipient of the message to the last person in the chain. Implications of the findings for crisis and emergency risk communication are discussed.

  8. Backaction-driven, robust, steady-state long-distance qubit entanglement over lossy channels

    Science.gov (United States)

    Motzoi, Felix; Halperin, Eli; Wang, Xiaoting; Whaley, K. Birgitta; Schirmer, Sophie

    2016-09-01

    We present a scheme for generating robust and persistent entanglement between qubits that do not interact and that are separated by a long and lossy transmission channel, using Markovian reservoir engineering. The proposal uses only the correlated decay into the common channel of remotely separated, driven single-photon qubit transitions. This simple scheme is generic and applicable to various experimental implementations, including circuit and cavity QED, with little experimental overhead compared with methods requiring dynamic control, initialization, measurement, or feedback. In addition to avoiding these inefficiencies, the simple protocol is highly robust against noise, miscalibration, and loss in the channel. We find high-quality solutions over a wide range of parameters and show that the optimal strategy reflects a transition from ballistic to diffusive photon transmission, going from symmetrically and coherently driving a common steady state to asymmetrically absorbing photons that are emitted from one qubit by the second. Detailed analysis of the role of the transmission channel shows that allowing bidirectional decay drastically increases indistinguishability and thereby quadratically suppresses infidelity.

  9. Quantum channels with a finite memory

    CERN Document Server

    Bowen, G; Bowen, Garry; Mancini, Stefano

    2004-01-01

    In this paper we study quantum communication channels with correlated noise effects, i.e., quantum channels with memory. We derive a model for correlated noise channels that includes a channel memory state. We examine the case where the memory is finite, and derive bounds on the classical and quantum capacities. For the entanglement-assisted and unassisted classical capacities it is shown that these bounds are attainable for certain classes of channel. Also, we show that the structure of any finite memory state is unimportant in the asymptotic limit, and specifically, for a perfect finite-memory channel where no information is lost to the environment, the channel is asymptotically noiseless.

  10. The State of Information and Communication Technology in Iran

    Directory of Open Access Journals (Sweden)

    Mohsen Gerami

    2010-03-01

    Full Text Available The development of information and communicationtechnologies depend on several factors like government policythat encourage investors to spend their money in building ITinfrastructure and force business or particular institution toadopt the new technologies to bring the price down and manyothers. This paper investigates the state of Information andCommunication Technology in Iran.

  11. Is Information Science an Anomalous State of Knowledge

    DEFF Research Database (Denmark)

    Hollnagel, E.

    1980-01-01

    it is not necessary for sciences which concern themselves with behavioral phenomena which have a prior description in natural language. It is further argued that information science should be more interested in uncertainty than in information, and it is shown how the Anomalous State of Knowledge (ASK) paradigm may...

  12. State FFA Officers' Confidence and Trustworthiness of Biotechnology Information Sources

    Science.gov (United States)

    Wingenbach, Gary J.; Rutherford, Tracy A.

    2007-01-01

    Are state FFA officers' awareness levels of agricultural topics reported in mass media superior to those who do not serve in leadership roles? The purpose of this study was to determine elected state FFA officers' awareness of biotechnology, and their confidence and trust of biotechnology information sources. Descriptive survey methods were used…

  13. Role of hippocampal CA1 area gap junction channels on morphine state-dependent learning.

    Science.gov (United States)

    Beheshti, Siamak; Hosseini, Seyyed Akbar Mir Seyyed; Noorbakhshnia, Maryam; Eivani, Mehdi

    2014-12-15

    Morphine produces a state dependent learning. The hippocampus is involved in this kind of learning. Gap junctions (GJs) are involved in some of the effects of morphine and exist in different areas of the hippocampus. We investigated the effects of blocking GJ channels of the hippocampal CA1 area, by means of pre-test bilateral injection of carbenoxolone (CBX), on morphine state dependent learning, using a passive avoidance task. Post-training subcutaneous administrations of morphine (0.5, 2.5, 5 and 7.5 mg/kg) dose-dependently impaired memory retrieval. Pre-test administration of morphine (0.5, 2.5, 5 and 7.5 mg/kg) induced a state-dependent retrieval of the memory acquired under post-training morphine influence. Pre-test injections of CBX (25, 75 and 150 nM) dose dependently prevented memory retrieval by post-training (7.5 mg/kg) and pre-test (0.5, 2.5, 5, 7.5 mg/kg) injections of morphine. The results suggest that intercellular coupling via GJ channels of the hippocampal CA1 area modulates morphine state dependent learning.

  14. State Data Centers: improving access to census information.

    Science.gov (United States)

    Redmond, M

    1986-01-01

    "The U.S. Bureau of the Census created the State Data Center program in 1978 to improve public access to census information. This article discusses the background, structure, and services of that program; the role of libraries in the program; and future directions in State Data Center/library relationships. The appendix lists contact person names, as well as addresses and telephone numbers for State Data Center lead agencies."

  15. Cloud Information Content Analysis for EPIC's Oxygen A- and B-band Channels

    Science.gov (United States)

    Davis, A. B.; Sanghavi, S.

    2011-12-01

    The Earth Polychromatic Imaging Camera (EPIC) instrument on the Deep Space Climate Observatory (DSCOVR) will have two molecular oxygen channels: one for the well-known ``A'' band at~764 nm and one for the weaker ``B'' band at 688~nm. In both cases, a channel-integrated relative measurement of absorption is possible using an ``in-band'' channel and a nearby ``reference'' channel. Together, these four observations enable a rudimentary differential optical absorption spectroscopy (DOAS) of O2 in the characteristic retro-reflection geometry of the L1 vantage point. A priori, we thus have at best two new pieces of cloud information to access. EPIC's pixels have 10x10 km2 footprints at nadir (center of the illuminated disk), more as the viewing angle increases away from local zenith. What new information can be learned about clouds from these data on a pixel-by-pixel basis? O2 A-band observations from space have been pioneered with CNES's POLDER, ESA's SCIAMACHY, and JAXA's GOSat. NASA's OCO-2, to be launched in early 2013, will also have A-band capability. POLDER has low spectral and spatial resolutions, but offers multiple viewing directions for every pixel; SCIAMACHY has higher spectral but worse spatial resolution and just one viewing angle. GOSat has very high spectral but rather low spatial resolutions, again with the possibility of dense angular sampling, but no imaging (just one pixel at a time). OCO-2, a narrow swath imager, will have similarly high spectral resolution and reasonably high ( ˜2~km) spatial resolution. Of these four LEO missions, two are focused on CO2 DOAS, with O2 being assayed operationally only to deliver it in ppm's. POLDER and SCIAMACHY however have official cloud products based on A-band measurements. They contain, at the least, an estimate of cloud top height and, at the most, that plus an estimate of cloud pressure thickness. Cloud optical depth and effective particle size are derived from other spectral data, including continuum values

  16. Holographic entanglement and causal information in coherent states

    Energy Technology Data Exchange (ETDEWEB)

    Gentle, Simon A. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Rangamani, Mukund [Centre for Particle Theory & Department of Mathematical Sciences, Lower Mountjoy, South Road, Durham DH1 3LE (United Kingdom)

    2014-01-22

    Scalar solitons in global AdS{sub 4} are holographically dual to coherent states carrying a non-trivial condensate of a scalar operator. We study the holographic information content of these states, focusing on a particular spatial region, by examining the entanglement entropy and causal holographic information. We show generically that whenever the dimension of the condensed operator is sufficiently low (characterized by the double-trace operator becoming relevant), such coherent states have lower entanglement and causal holographic information than the vacuum state of the system, despite having greater energy. We also use these geometries to illustrate the fact that causal wedges associated with a simply-connected boundary region can have non-trivial topology even in causally trivial spacetimes.

  17. Undermining the state? Informal mining and trajectories of state formation in Eastern Mindanao, Philippines

    NARCIS (Netherlands)

    Verbrugge, B.L.P.

    2015-01-01

    Building on critical perspectives on the state and the informal economy, this article provides an analysis of the “state of the state” on the eastern Mindanao mineral frontier. In the first instance, the author explains that the massive expansion of informal small-scale gold mining, instead of under

  18. Missouri State information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-31

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the State of Missouri. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature chairmen, and a summary of recent relevant legislative action; a description of the organization and structure of local governments affected by remedial action at the St. Louis area sites; a summary of relevant local ordinances and regulations; an identification of relevant public interest groups; a list of radio stations, television stations, and newspapers that provide public information to the St. Louis area or to Jefferson City; and the full text of relevant statutes and regulations.

  19. An Optimal Transmission Strategy for Joint Wireless Information and Energy Transfer in MIMO Relay Channels

    Directory of Open Access Journals (Sweden)

    Dingcheng Yang

    2015-01-01

    Full Text Available An optimal resource allocation strategy for MIMO relay system is considered in simultaneous wireless information and energy transfer network, where two users with multiple antennas communicate with each other assisted by an energy harvesting MIMO relay that gathers energy from the received signal by applying time switching scheme and forwards the received signal by using the harvesting energy. It is focused on the precoder design and resource allocation strategies for the system to allocate the resources among the nodes in decode-and-forward (DF mode. Specifically, optimal precoder design and energy transfer strategy in MIMO relay channel are firstly proposed. Then, we formulate the resource allocation optimization problem. The closed-form solutions for the time and power allocation are derived. It is revealed that the solution can flexibly allocate the resource for the MIMO relay channel to maximize the sum rate of the system. Simulation results demonstrated that the performance of the proposed algorithm outperforms the traditional fixed method.

  20. Information content in cortical spike trains during brain state transitions.

    Science.gov (United States)

    Arnold, Maria M; Szczepanski, Janusz; Montejo, Noelia; Amigó, José M; Wajnryb, Eligiusz; Sanchez-Vives, Maria V

    2013-02-01

    Even in the absence of external stimuli there is ongoing activity in the cerebral cortex as a result of recurrent connectivity. This paper attempts to characterize one aspect of this ongoing activity by examining how the information content carried by specific neurons varies as a function of brain state. We recorded from rats chronically implanted with tetrodes in the primary visual cortex during awake and sleep periods. Electro-encephalogram and spike trains were recorded during 30-min periods, and 2-4 neuronal spikes were isolated per tetrode off-line. All the activity included in the analysis was spontaneous, being recorded from the visual cortex in the absence of visual stimuli. The brain state was determined through a combination of behavior evaluation, electroencephalogram and electromyogram analysis. Information in the spike trains was determined by using Lempel-Ziv Complexity. Complexity was used to estimate the entropy of neural discharges and thus the information content (Amigóet al. Neural Comput., 2004, 16: 717-736). The information content in spike trains (range 4-70 bits s(-1) ) was evaluated during different brain states and particularly during the transition periods. Transitions toward states of deeper sleep coincided with a decrease of information, while transitions to the awake state resulted in an increase in information. Changes in both directions were of the same magnitude, about 30%. Information in spike trains showed a high temporal correlation between neurons, reinforcing the idea of the impact of the brain state in the information content of spike trains.

  1. Multi-Photon Multi-Channel Interferometry for Quantum Information Processing

    CERN Document Server

    Dhand, Ish

    2016-01-01

    This thesis reports advances in the theory of design, characterization and simulation of multi-photon multi-channel interferometers. I advance the design of interferometers through an algorithm to realize an arbitrary discrete unitary transformation on the combined spatial and internal degrees of freedom of light. This procedure effects an arbitrary $n_{s}n_{p}\\times n_{s}n_{p}$ unitary matrix on the state of light in $n_{s}$ spatial and $n_{p}$ internal modes. I devise an accurate and precise procedure for characterizing any multi-port linear optical interferometer using one- and two-photon interference. Accuracy is achieved by estimating and correcting systematic errors that arise due to spatiotemporal and polarization mode mismatch. Enhanced accuracy and precision are attained by fitting experimental coincidence data to a curve simulated using measured source spectra. The efficacy of our characterization procedure is verified by numerical simulations. I develop group-theoretic methods for the analysis and ...

  2. Inform, influence, evaluate: the power of state public opinion polls.

    Science.gov (United States)

    Turner, Shiloh; O'Connor, Patricia; Rademacher, Eric

    2009-01-01

    Politicians use public opinion polling data if the data are available to them. Most of these data are from national polls and do not allow for state-level analysis. One promising strategy for informing elected state officials about health issues is to administer public opinion polls at the state level. Combined with health assessment surveys, public opinion data provide a powerful tool for health policy development. This Report reviews one regional foundation's efforts at providing public opinion poll data at the state level and the results of these efforts.

  3. Effective information channels for reducing costs of environmentally- friendly technologies: evidence from residential PV markets

    Science.gov (United States)

    Rai, Varun; Robinson, Scott A.

    2013-03-01

    Realizing the environmental benefits of solar photovoltaics (PV) will require reducing costs associated with perception, informational gaps and technological uncertainties. To identify opportunities to decrease costs associated with residential PV adoption, in this letter we use multivariate regression models to analyze a unique, household-level dataset of PV adopters in Texas (USA) to systematically quantify the effect of different information channels on aspiring PV adopters’ decision-making. We find that the length of the decision period depends on the business model, such as whether the system was bought or leased, and on special opportunities to learn, such as the influence of other PV owners in the neighborhood. This influence accrues passively through merely witnessing PV systems in the neighborhood, increasing confidence and motivation, as well as actively through peer-to-peer communications. Using these insights we propose a new framework to provide public information on PV that could drastically reduce barriers to PV adoption, thereby accelerating its market penetration and environmental benefits. This framework could also serve as a model for other distributed generation technologies.

  4. Effects of information transmission delay and channel blocking on synchronization in scale-free Hodgkin-Huxley neuronal networks

    Institute of Scientific and Technical Information of China (English)

    Qing-Yun Wang; Yan-Hong Zheng

    2011-01-01

    In this paper,we investigate the evolution of spatiotemporal patterns and synchronization transitions in dependence on the information transmission delay and ion channel blocking in scale-free neuronal networks.As the underlying model of neuronal dynamics,we use the HodgkinHuxley equations incorporating channel blocking and intrinsic noise.It is shown that delays play a significant yet subtle role in shaping the dynamics of neuronal networks.In particular,regions of irregular and regular propagating excitatory fronts related to the synchronization transitions appear intermittently as the delay increases.Moreover,the fraction of working sodium and potassium ion channels can also have a significant impact on the spatiotemporal dynamics of neuronal networks.As the fraction of blocked sodium channels increases,the frequency of excitatory events decreases,which in turn manifests as an increase in the neuronal synchrony that,however,is dysfunctional due to the virtual absence of large-amplitude excitations.Expectedly,we also show that larger coupling strengths improve synchronization irrespective of the information transmission delay and channel blocking.The presented results are also robust against the variation of the network size,thus providing insights that could facilitate understanding of the joint impact of ion channel blocking and information transmission delay on the spatiotemporal dynamics of neuronal networks.

  5. Effects of information transmission delay and channel blocking on synchronization in scale-free Hodgkin-Huxley neuronal networks

    Science.gov (United States)

    Wang, Qing-Yun; Zheng, Yan-Hong

    2011-12-01

    In this paper, we investigate the evolution of spatiotemporal patterns and synchronization transitions in dependence on the information transmission delay and ion channel blocking in scale-free neuronal networks. As the underlying model of neuronal dynamics, we use the Hodgkin-Huxley equations incorporating channel blocking and intrinsic noise. It is shown that delays play a significant yet subtle role in shaping the dynamics of neuronal networks. In particular, regions of irregular and regular propagating excitatory fronts related to the synchronization transitions appear intermittently as the delay increases. Moreover, the fraction of working sodium and potassium ion channels can also have a significant impact on the spatiotemporal dynamics of neuronal networks. As the fraction of blocked sodium channels increases, the frequency of excitatory events decreases, which in turn manifests as an increase in the neuronal synchrony that, however, is dysfunctional due to the virtual absence of large-amplitude excitations. Expectedly, we also show that larger coupling strengths improve synchronization irrespective of the information transmission delay and channel blocking. The presented results are also robust against the variation of the network size, thus providing insights that could facilitate understanding of the joint impact of ion channel blocking and information transmission delay on the spatiotemporal dynamics of neuronal networks.

  6. The HIVE Tool for Informed Swarm State Space Exploration

    CERN Document Server

    Wijs, Anton

    2011-01-01

    Swarm verification and parallel randomised depth-first search are very effective parallel techniques to hunt bugs in large state spaces. In case bugs are absent, however, scalability of the parallelisation is completely lost. In recent work, we proposed a mechanism to inform the workers which parts of the state space to explore. This mechanism is compatible with any action-based formalism, where a state space can be represented by a labelled transition system. With this extension, each worker can be strictly bounded to explore only a small fraction of the state space at a time. In this paper, we present the HIVE tool together with two search algorithms which were added to the LTSmin tool suite to both perform a preprocessing step, and execute a bounded worker search. The new tool is used to coordinate informed swarm explorations, and the two new LTSmin algorithms are employed for preprocessing a model and performing the individual searches.

  7. Continuous variable quantum information: Gaussian states and beyond

    CERN Document Server

    Adesso, Gerardo; Lee, Antony R

    2014-01-01

    The study of Gaussian states has arisen to a privileged position in continuous variable quantum information in recent years. This is due to vehemently pursued experimental realisations and a magnificently elegant mathematical framework. In this article, we provide a brief, and hopefully didactic, exposition of Gaussian state quantum information and its contemporary uses, including sometimes omitted crucial details. After introducing the subject material and outlining the essential toolbox of continuous variable systems, we define the basic notions needed to understand Gaussian states and Gaussian operations. In particular, emphasis is placed on the mathematical structure combining notions of algebra and symplectic geometry fundamental to a complete understanding of Gaussian informatics. Furthermore, we discuss the quantification of different forms of correlations (including entanglement and quantum discord) for Gaussian states, paying special attention to recently developed measures. The manuscript is conclud...

  8. Quantum information theory of the Bell-state quantum eraser

    Science.gov (United States)

    Glick, Jennifer R.; Adami, Christoph

    2017-01-01

    Quantum systems can display particle- or wavelike properties, depending on the type of measurement that is performed on them. The Bell-state quantum eraser is an experiment that brings the duality to the forefront, as a single measurement can retroactively be made to measure particlelike or wavelike properties (or anything in between). Here we develop a unitary information-theoretic description of this and several related quantum measurement situations that sheds light on the trade-off between the quantum and classical features of the measurement. In particular, we show that both the coherence of the quantum state and the classical information obtained from it can be described using only quantum-information-theoretic tools and that those two measures satisfy an equality on account of the chain rule for entropies. The coherence information and the which-path information have simple interpretations in terms of state preparation and state determination and suggest ways to account for the relationship between the classical and the quantum world.

  9. Remote atomic information concentration without Bell-state measurement

    Institute of Scientific and Technical Information of China (English)

    Wu Zhen-Zhen; Fang Mao-Fa

    2006-01-01

    This paper proposes a scheme for information concentration of two remote two-level atoms in cavity QED. This scheme does not involve the Bell-state measurement. During the interaction between atom and cavity, the cavity frequency is large-detuned from the atomic transition frequency, thus the scheme is insensitive to both the cavity decay and the thermal field. This idea can directly be generalized in the case of multi-atom information concentration.

  10. Quantum information processing using designed defect states in

    DEFF Research Database (Denmark)

    Pedersen, Jesper; Flindt, Christian; Mortensen, Niels Asger

    2007-01-01

    We propose a new physical implementation of spin qubits for quantum information processing, namely defect states in antidot lattices de¯ned in the two-dimensional electron gas at a semiconductor heterostructure. Calculations of the band structure of the periodic antidot lattice are presented......-coupled defect states is calculated numerically.We ¯nd results reminiscent of double quantum dot structures, indicating that the suggested structure is a feasible physical implementation of spin qubits....

  11. Exact coherent states and connections to turbulent dynamics in minimal channel flow

    CERN Document Server

    Park, Jae Sung

    2015-01-01

    Several new families of nonlinear three-dimensional travelling wave solutions to the Navier-Stokes equation, also known as exact coherent states, are computed for Newtonian plane Poiseuille flow. The symmetries and streak/vortex structures are reported and their possible connections to critical layer dynamics examined. While some of the solutions clearly display fluctuations that are localized around the critical layer (the surface on which the streamwise velocity matches the wave speed of the solution), for others this connection is not as clear. Dynamical trajectories along unstable directions of the solutions are computed. Over certain ranges of Reynolds number, two solution families are shown to lie on the basin boundary between laminar and turbulent flow. Direct comparison of nonlinear travelling wave solutions to turbulent flow in the same channel is presented. The state-space dynamics of the turbulent flow are organized around one of the newly-identified travelling wave families, and in particular the ...

  12. Single-channel kinetics of BK (Slo1 channels

    Directory of Open Access Journals (Sweden)

    Yanyan eGeng

    2015-01-01

    Full Text Available Single-channel kinetics has proven a powerful tool to reveal information about the gating mechanisms that control the opening and closing of ion channels. This introductory review focuses on the gating of large conductance Ca2+- and voltage-activated K+ (BK or Slo1 channels at the single-channel level. It starts with single-channel current records and progresses to presentation and analysis of single-channel data and the development of gating mechanisms in terms of discrete state Markov (DSM models. The DSM models are formulated in terms of the tetrameric modular structure of BK channels, consisting of a central transmembrane pore-gate domain (PGD attached to four surrounding transmembrane voltage sensing domains (VSD and a large intracellular cytosolic domain (CTD, also referred to as the gating ring. The modular structure and data analysis shows that the Ca2+ and voltage dependent gating considered separately can each be approximated by 10-state two-tiered models with 5 closed states on the upper tier and 5 open states on the lower tier. The modular structure and joint Ca2+ and voltage dependent gating are consistent with a 50 state two-tiered model with 25 closed states on the upper tier and 25 open states on the lower tier. Adding an additional tier of brief closed (flicker states to the 10-state or 50-state models improved the description of the gating. For fixed experimental conditions a channel would gate in only a subset of the potential number of states. The detected number of states and the correlations between adjacent interval durations are consistent with the tiered models. The examined models can account for the single-channel kinetics and the bursting behavior of gating. Ca2+ and voltage activate BK channels by predominantly increasing the effective opening rate of the channel with a smaller decrease in the effective closing rate. Ca2+ and depolarization thus activate by mainly destabilizing the closed states.

  13. Information channel effects on women intention to purchase irradiated food in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Myung-Woo; Oh, Sang-Hee; Kim, Jae-Hun; Yoon, Yohan [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Park, Seong-Cheol; Kim, Hak-Soo [Department of Communication Arts, Sogang University, Seoul 121-742 (Korea, Republic of); Kim, Soon-Bok [Korean Federation of Housewives Clubs, Seoul 100-804 (Korea, Republic of); Han, Sang-Bae [Food and Risk Standardization Team, Korea Food and Drug Administration, Seoul 122-704 (Korea, Republic of); Lee, Ju-Woon [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    Since the first irradiated food was approved and commercialized in 1987, most of Koreans still do not accept the irradiated food until now. It is reasoned that there are the ambiguous fear of nuclear technology and the confusion between irradiated food and radioactive-contaminated food. This investigation was carried out to examine the acknowledgement of irradiated food in Korean housewives and to study how to enhance the intention of purchasing the irradiated food. About 600 Korean housewives participated in the survey on the irradiated food in 2007, more than two-thirds of them were not aware of irradiated food. One hundred and fifty-four women who had known of irradiated food were subjected to an experiment for the source of information about irradiated food (e.g., lecture by an expert, video-watching and book-reading) in order to explore which type of information channel is the most effective in eliciting purchase intention. The result showed that the women group who had heard the lecture by an expert indicated the highest intention to purchase irradiated food, followed by the video-watching and the book-reading groups. In addition, the acceptance of the irradiated food had shown to lead the support for nuclear industry.

  14. Information channel effects on women intention to purchase irradiated food in Korea

    Science.gov (United States)

    Byun, Myung-Woo; Oh, Sang-Hee; Kim, Jae-Hun; Yoon, Yohan; Park, Seong-Cheol; Kim, Hak-Soo; Kim, Soon-Bok; Han, Sang-Bae; Lee, Ju-Woon

    2009-07-01

    Since the first irradiated food was approved and commercialized in 1987, most of Koreans still do not accept the irradiated food until now. It is reasoned that there are the ambiguous fear of nuclear technology and the confusion between irradiated food and radioactive-contaminated food. This investigation was carried out to examine the acknowledgement of irradiated food in Korean housewives and to study how to enhance the intention of purchasing the irradiated food. About 600 Korean housewives participated in the survey on the irradiated food in 2007, more than two-thirds of them were not aware of irradiated food. One hundred and fifty-four women who had known of irradiated food were subjected to an experiment for the source of information about irradiated food (e.g., lecture by an expert, video-watching and book-reading) in order to explore which type of information channel is the most effective in eliciting purchase intention. The result showed that the women group who had heard the lecture by an expert indicated the highest intention to purchase irradiated food, followed by the video-watching and the book-reading groups. In addition, the acceptance of the irradiated food had shown to lead the support for nuclear industry.

  15. FMRP Regulates Neurotransmitter Release and Synaptic Information Transmission by Modulating Action Potential Duration via BK channels

    Science.gov (United States)

    Deng, Pan-Yue; Rotman, Ziv; Blundon, Jay A.; Cho, Yongcheol; Cui, Jianmin; Cavalli, Valeria; Zakharenko, Stanislav S.; Klyachko, Vitaly A.

    2013-01-01

    SUMMARY Loss of FMRP causes Fragile X syndrome (FXS), but the physiological functions of FMRP remain highly debatable. Here we show that FMRP regulates neurotransmitter release in CA3 pyramidal neurons by modulating action potential (AP) duration. Loss of FMRP leads to excessive AP broadening during repetitive activity, enhanced presynaptic calcium influx and elevated neurotransmitter release. The AP broadening defects caused by FMRP loss have a cell-autonomous presynaptic origin and can be acutely rescued in postnatal neurons. These presynaptic actions of FMRP are translation-independent and are mediated selectively by BK channels via interaction of FMRP with BK channel’s regulatory β4 subunits. Information-theoretical analysis demonstrates that loss of these FMRP functions causes marked dysregulation of synaptic information transmission. FMRP-dependent AP broadening is not limited to the hippocampus, but also occurs in cortical pyramidal neurons. Our results thus suggest major translation-independent presynaptic functions of FMRP that may have important implications for understanding FXS neuropathology. PMID:23439122

  16. Multifaceted determinants of online non-prescription drug information seeking and the impact on consumers' use of purchase channels.

    Science.gov (United States)

    Holtgräfe, Catherine; Zentes, Joachim

    2012-06-01

    The growing importance of the Internet as an information and purchasing channel is drawing widespread attention from marketing decision makers. Nevertheless, the relevance of the Internet to the so-called self-medication market in Germany has been paid barely enough attention. Our study aims to contribute insights concerning the penetration of the Internet in this market, as well as to give an overview of the critical determinants of Internet use for non-prescription drug information seeking, such as the accessibility of professional information, trust in health professionals' opinion and the ability to search online, as well as the perceived usefulness and credibility of online non-prescription drug information. Furthermore, we demonstrate that the preferred use of the Internet as a non-prescription drug information source positively influences the choice of unconventional purchase channels for non-prescription drugs and negatively affects the use of stationary pharmacies.

  17. D-branes as coherent states in the open string channel

    CERN Document Server

    Cantcheff, Marcelo Botta

    2007-01-01

    We show that bosonic D-brane states may be represented as coherent states in an open string representation. By using the Thermo Field Dynamics (TFD) formalism, we may construct a condensed state of open string modes which encodes the information on the D-brane configuration. We also introduce a construction alternative to TFD, which does not require to assume thermal equilibrium. It is shown that the dynamics of the system, combined with geometric properties of the duplication rules of TFD, is sufficient to obtain the thermal states and their analytic continuations in a geometric fashion. We adopt this approach to show that bosonic D-brane states in the open string sector may also be built as boundary states in a special sense. Some implications of this study on the interpretation of the open/closed duality and on the kinematical/algebraic structure of an open string field theory are also commented.

  18. State preparation for quantum information science and metrology

    Energy Technology Data Exchange (ETDEWEB)

    Samblowski, Aiko

    2012-06-08

    The precise preparation of non-classical states of light is a basic requirement for performing quantum information tasks and quantum metrology. Depending on the assignment, the range of required states varies from preparing and modifying squeezed states to generating bipartite entanglement and establishing multimode entanglement networks. Every state needs special preparation techniques and hence it is important to develop the experimental expertise to generate all states with the desired degree of accuracy. In this thesis, the experimental preparation of different kinds of non-classical states of light is demonstrated. Starting with a multimode entangled state, the preparation of an unconditionally generated bound entangled state of light of unprecedented accuracy is shown. Its existence is of fundamental interest, since it certifies an intrinsic irreversibility of entanglement and suggests a connection with thermodynamics. The state is created in a network of linear optics, utilizing optical parametric amplifiers, operated below threshold, beam splitters and phase gates. The experimental platform developed here afforded the precise and stable control of all experimental parameters. Focusing on the aspect of quantum information networks, the generation of suitable bipartite entangled states of light is desirable. The optical connection between atomic transitions and light that can be transmitted via telecommunications fibers opens the possibility to employ quantum memories within fiber networks. For this purpose, a non-degenerate optical parametric oscillator is operated above threshold and the generation of bright bipartite entanglement between its twin beams at the wavelengths of 810 nm and 1550 nm is demonstrated. In the field of metrology, quantum states are used to enhance the measurement precision of interferometric gravitational wave (GW) detectors. Recently, the sensitivity of a GW detector operated at a wavelength of 1064 nm was increased using squeezed

  19. Design and Simulation of Multi-state Network Covert Timing Channel%多进制网络时间隐蔽信道设计及仿真实现

    Institute of Scientific and Technical Information of China (English)

    裴勇; 孙玉娣

    2011-01-01

    Binary-Encoding network covert timing channel, which greatly influenced by the network status, has limited channel capacity and less transmitted information. For improving the capacity of covert channel in complex network situation, multi-state network covert timing channel was proposed. Through analysis of the channel capacity, the feasibility of multi-state channel was proved and three types of multi-state channel were designed; according to single path network, the calculation units to distinguish between different encodings of various channels was analyzed to ensure the effectiveness of channel. The results of simulation show that the proposed multi-state network covert timing channels with higher channel capacity and all have their own characteristics and the practical value.%基于二进制编码的网络时间隐蔽信道,信道容量有限,可传输信息量较少,受网络状态的影响较大.为在较复杂网络状况下,有效提高隐蔽信道的容量,提出了多进制网络时间隐蔽信道的设计.通过信道容量分析,得出多进制通道的可行性,并设计三种通道实现方式;针对单路径下延迟抖动特点,分析各种通道区分不同编码的计算单位,保证通道的有效性.仿真实例结果表明,提出的三种多进制网络时间隐蔽信道具有较高的信道容量,各有特点和实用价值.

  20. Asymmetric ion transport through ion-channel-mimetic solid-state nanopores.

    Science.gov (United States)

    Guo, Wei; Tian, Ye; Jiang, Lei

    2013-12-17

    Both scientists and engineers are interested in the design and fabrication of synthetic nanofluidic architectures that mimic the gating functions of biological ion channels. The effort to build such structures requires interdisciplinary efforts at the intersection of chemistry, materials science, and nanotechnology. Biological ion channels and synthetic nanofluidic devices have some structural and chemical similarities, and therefore, they share some common features in regulating the traverse ionic flow. In the past decade, researchers have identified two asymmetric ion transport phenomena in synthetic nanofluidic structures, the rectified ionic current and the net diffusion current. The rectified ionic current is a diode-like current-voltage response that occurs when switching the voltage bias. This phenomenon indicates a preferential direction of transport in the nanofluidic system. The net diffusion current occurs as a direct product of charge selectivity and is generated from the asymmetric diffusion through charged nanofluidic channels. These new ion transport phenomena and the elaborate structures that occur in biology have inspired us to build functional nanofluidic devices for both fundamental research and practical applications. In this Account, we review our recent progress in the design and fabrication of biomimetic solid-state nanofluidic devices with asymmetric ion transport behavior. We demonstrate the origin of the rectified ionic current and the net diffusion current. We also identify several influential factors and discuss how to build these asymmetric features into nanofluidic systems by controlling (1) nanopore geometry, (2) surface charge distribution, (3) chemical composition, (4) channel wall wettability, (5) environmental pH, (6) electrolyte concentration gradient, and (7) ion mobility. In the case of the first four features, we build these asymmetric features directly into the nanofluidic structures. With the final three, we construct

  1. Athermalized channeled spectropolarimeter enhancement.

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Julia Craven; Way, Brandyn Michael; Mercier, Jeffrey Alan; Hunt, Jeffery P.

    2013-09-01

    Channeled spectropolarimetry can measure the complete polarization state of light as a function of wavelength. Typically, a channeled spectropolarimeter uses high order retarders made of uniaxial crystal to amplitude modulate the measured spectrum with the spectrally-dependent Stokes polarization information. A primary limitation of conventional channeled spectropolarimeters is related to the thermal variability of the retarders. Thermal variation often forces frequent system recalibration, particularly for field deployed systems. However, implementing thermally stable retarders, made of biaxial crystal, results in an athermal channeled spectropolarimeter that relieves the need for frequent recalibration. This report presents experimental results for an anthermalized channeled spectropolarimeter prototype produced using potassium titanyl phosphate. The results of this prototype are compared to the current thermal stabilization state of the art. Finally, the application of the technique to the thermal infrared is studied, and the athermalization concept is applied to an infrared imaging spectropolarimeter design.

  2. Entanglement and purity of two-mode Gaussian states in noisy channels

    CERN Document Server

    Serafini, A; Paris, M G A; De Siena, S; Serafini, Alessio; Illuminati, Fabrizio; Paris, Matteo G. A.; Siena, Silvio De

    2004-01-01

    We study the evolution of purity, entanglement and total correlations of general two--mode Gaussian states of continuous variable systems in arbitrary uncorrelated Gaussian environments. The time evolution of purity, Von Neumann entropy, logarithmic negativity and mutual information is analyzed for a wide range of initial conditions. In general, we find that a local squeezing of the bath leads to a faster degradation of purity and entanglement, while it can help to preserve the mutual information between the modes.

  3. Generation of optical coherent state superpositions for quantum information processing

    DEFF Research Database (Denmark)

    Tipsmark, Anders

    2012-01-01

    I dette projektarbejde med titlen “Generation of optical coherent state superpositions for quantum information processing” har målet været at generere optiske kat-tilstande. Dette er en kvantemekanisk superpositions tilstand af to koherente tilstande med stor amplitude. Sådan en tilstand er...

  4. Dynamics of sensory thalamocortical synaptic networks during information processing states.

    Science.gov (United States)

    Castro-Alamancos, Manuel A

    2004-11-01

    The thalamocortical network consists of the pathways that interconnect the thalamus and neocortex, including thalamic sensory afferents, corticothalamic and thalamocortical pathways. These pathways are essential to acquire, analyze, store and retrieve sensory information. However, sensory information processing mostly occurs during behavioral arousal, when activity in thalamus and neocortex consists of an electrographic sign of low amplitude fast activity, known as activation, which is caused by several neuromodulator systems that project to the thalamocortical network. Logically, in order to understand how the thalamocortical network processes sensory information it is essential to study its response properties during states of activation. This paper reviews the temporal and spatial response properties of synaptic pathways in the whisker thalamocortical network of rodents during activated states as compared to quiescent (non-activated) states. The evidence shows that these pathways are differentially regulated via the effects of neuromodulators as behavioral contingencies demand. Thus, during activated states, the temporal and spatial response properties of pathways in the thalamocortical network are transformed to allow the processing of sensory information.

  5. Online Information. Selected Databases at the New York State Library.

    Science.gov (United States)

    New York State Library, Albany. Database Services.

    This brochure describes the online information services at the New York State Library, which has online access to over 250 databases covering a broad range of subject areas, including current events, law, science, medicine, public affairs, grants, business, computer technology, education, social welfare, and humanities. Many of these databases are…

  6. Fisher Information and entanglement of non-Gaussian spin states

    CERN Document Server

    Strobel, Helmut; Linnemann, Daniel; Zibold, Tilman; Hume, David B; Pezzè, Luca; Smerzi, Augusto; Oberthaler, Markus K

    2015-01-01

    Entanglement is the key quantum resource for improving measurement sensitivity beyond classical limits. However, the production of entanglement in mesoscopic atomic systems has been limited to squeezed states, described by Gaussian statistics. Here we report on the creation and characterization of non-Gaussian many-body entangled states. We develop a general method to extract the Fisher information, which reveals that the quantum dynamics of a classically unstable system creates quantum states that are not spin squeezed but nevertheless entangled. The extracted Fisher information quantifies metrologically useful entanglement which we confirm by Bayesian phase estimation with sub shot-noise sensitivity. These methods are scalable to large particle numbers and applicable directly to other quantum systems.

  7. Hypothyroid state reduces calcium channel function in 18-day pregnant rat uterus.

    Science.gov (United States)

    Parija, S C; Mishra, S K; Raviprakash, V

    2006-01-01

    Hypothyroidism significantly reduced the mean amplitude and increased the mean frequency of spontaneous rhythmic contractions in 18 day pregnant rat uterus. Nifedipine (10(-12)-10(-9) M) and diltiazem (10(-10)-10(-6) M) caused concentration related inhibition of the myogenic responses of the uterine strips obtained from both pregnant and hypothyroid state. However, nifedipine was less potent (IC50:2.11 x 10(-11) M) in pregnant hypothyroid state as compared to pregnant control (IC50: 3.1 x 10(-12) M). Similarly, diltiazem was less potent (IC50: 3.72 x 10(-9) M) in inhibiting the uterine spontaneous contractions in hypothyroid than in pregnant rat uterus (IC50:5.37 x 10(-10) M). A similar decrease in the sensitivity to nifedipine and diltiazem for reversal of K+ (100 mM)-induced tonic contraction and K(+)-stimulated 45Ca2+ influx was observed with these calcium channel antagonists in uterus obtained from hypothyroid pregnant rats compared to the controls. Nifedipine-sensitive influx of 45Ca(2+)-stimulated either by K+ (100 mM) or by Bay K8644 (1,4-dihydro-2,6-methyl-5-nitro-4-[2'-(trifluromethyl)phenyl]-3-pyridine carboxylic acid methyl ester) (10(-9) M) was significantly less in uterine strips from hypothyroid rats compared to controls. The results suggest that the inhibition of uterine rhythmic contractions may be attributable to a reduction in rat myometrial Ca2+ channel function in the hypothyroid state.

  8. Optimal Conclusive Teleportation of an Arbitrary d-Dimensional N-Particle Unknown State via a Partially Entangled Quantum Channel

    Institute of Scientific and Technical Information of China (English)

    HAO San-Ru; HOU Bo-Yu; XI Xiao-Qiang; YUE Rui-Hong

    2003-01-01

    In the paper we generalize the standard teleportation to the conclusive teleportation case which can teleportan arbitrary d-dimensional N-particle unknown state via the partially entangled quantum channel. We show that onlyif the quantum channel satisfies a constraint condition can the most general d-dimensional N-particle unknown state beperfect conclusively teleported. We also present a method for optimal conclusively teleportation of the N-particle statesand for constructing the joint POVM which can discern the quantum states on the sender's (Alice's) side. Two typicalexamples are given so that one can see how our method works.

  9. Trap density of states in n-channel organic transistors: variable temperature characteristics and band transport

    Directory of Open Access Journals (Sweden)

    Joung-min Cho

    2013-10-01

    Full Text Available We have investigated trap density of states (trap DOS in n-channel organic field-effect transistors based on N,N ’-bis(cyclohexylnaphthalene diimide (Cy-NDI and dimethyldicyanoquinonediimine (DMDCNQI. A new method is proposed to extract trap DOS from the Arrhenius plot of the temperature-dependent transconductance. Double exponential trap DOS are observed, in which Cy-NDI has considerable deep states, by contrast, DMDCNQI has substantial tail states. In addition, numerical simulation of the transistor characteristics has been conducted by assuming an exponential trap distribution and the interface approximation. Temperature dependence of transfer characteristics are well reproduced only using several parameters, and the trap DOS obtained from the simulated characteristics are in good agreement with the assumed trap DOS, indicating that our analysis is self-consistent. Although the experimentally obtained Meyer-Neldel temperature is related to the trap distribution width, the simulation satisfies the Meyer-Neldel rule only very phenomenologically. The simulation also reveals that the subthreshold swing is not always a good indicator of the total trap amount, because it also largely depends on the trap distribution width. Finally, band transport is explored from the simulation having a small number of traps. A crossing point of the transfer curves and negative activation energy above a certain gate voltage are observed in the simulated characteristics, where the critical VG above which band transport is realized is determined by the sum of the trapped and free charge states below the conduction band edge.

  10. Trap density of states in n-channel organic transistors: variable temperature characteristics and band transport

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Joung-min, E-mail: cho.j.ad@m.titech.ac.jp; Akiyama, Yuto; Kakinuma, Tomoyuki [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Tokyo 152-8552 (Japan); Mori, Takehiko [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, O-okayama, Tokyo 152-8552 (Japan); ACT-C, JST, Honcho, Kawaguchi, Saitama 332-0012 (Japan)

    2013-10-15

    We have investigated trap density of states (trap DOS) in n-channel organic field-effect transistors based on N,N ’-bis(cyclohexyl)naphthalene diimide (Cy-NDI) and dimethyldicyanoquinonediimine (DMDCNQI). A new method is proposed to extract trap DOS from the Arrhenius plot of the temperature-dependent transconductance. Double exponential trap DOS are observed, in which Cy-NDI has considerable deep states, by contrast, DMDCNQI has substantial tail states. In addition, numerical simulation of the transistor characteristics has been conducted by assuming an exponential trap distribution and the interface approximation. Temperature dependence of transfer characteristics are well reproduced only using several parameters, and the trap DOS obtained from the simulated characteristics are in good agreement with the assumed trap DOS, indicating that our analysis is self-consistent. Although the experimentally obtained Meyer-Neldel temperature is related to the trap distribution width, the simulation satisfies the Meyer-Neldel rule only very phenomenologically. The simulation also reveals that the subthreshold swing is not always a good indicator of the total trap amount, because it also largely depends on the trap distribution width. Finally, band transport is explored from the simulation having a small number of traps. A crossing point of the transfer curves and negative activation energy above a certain gate voltage are observed in the simulated characteristics, where the critical V{sub G} above which band transport is realized is determined by the sum of the trapped and free charge states below the conduction band edge.

  11. Efficient Processing of Acoustic Signals for High Rate Information Transmission over Sparse Underwater Channels

    Science.gov (United States)

    2016-09-02

    Institute of Technology Cmabridge, MA 02139 millitsa@mit.edu Abstract For underwater acoustic channels where multipath spread is measured in tens of symbol...eliminates the need for a separate channel estimator/equalizer for each array element. The advantages of this approach are reduction in the number of...of a large equalizer, it is possible to design an adaptive processing method that takes into account only the significant channel components. The

  12. New approach to information fusion for Lipschitz classifiers ensembles: Application in multi-channel C-OTDR-monitoring systems

    Science.gov (United States)

    Timofeev, Andrey V.; Egorov, Dmitry V.

    2016-06-01

    This paper presents new results concerning selection of an optimal information fusion formula for an ensemble of Lipschitz classifiers. The goal of information fusion is to create an integral classificatory which could provide better generalization ability of the ensemble while achieving a practically acceptable level of effectiveness. The problem of information fusion is very relevant for data processing in multi-channel C-OTDR-monitoring systems. In this case we have to effectively classify targeted events which appear in the vicinity of the monitored object. Solution of this problem is based on usage of an ensemble of Lipschitz classifiers each of which corresponds to a respective channel. We suggest a brand new method for information fusion in case of ensemble of Lipschitz classifiers. This method is called "The Weighing of Inversely as Lipschitz Constants" (WILC). Results of WILC-method practical usage in multichannel C-OTDR monitoring systems are presented.

  13. A novel quantum information hiding protocol based on entanglement swapping of high-level Bell states

    Science.gov (United States)

    Xu, Shu-Jiang; Chen, Xiu-Bo; Wang, Lian-Hai; Niu, Xin-Xin; Yang, Yi-Xian

    2015-05-01

    Using entanglement swapping of high-level Bell states, we first derive a covert layer between the secret message and the possible output results of the entanglement swapping between any two generalized Bell states, and then propose a novel high-efficiency quantum information hiding protocol based on the covert layer. In the proposed scheme, a covert channel can be built up under the cover of a high-level quantum secure direct communication (QSDC) channel for securely transmitting secret messages without consuming any auxiliary quantum state or any extra communication resource. It is shown that this protocol not only has a high embedding efficiency but also achieves a good imperceptibility as well as a high security. Project supported by the National Natural Science Foundation of China (Grant Nos. 61303199, 61272514, 61170272, 61121061, and 61411146001), the Shandong Provincial Natural Science Foundation of China (Grant Nos. ZR2013FM025, ZR2013FQ001, and ZR2014FM003), the Shandong Provincial Outstanding Research Award Fund for Young Scientists of China (Grant Nos. BS2013DX010 and BS2014DX007), the Program for New Century Excellent Talents in Universities, China (Grant No. NCET-13-0681), the National Development Foundation for Cryptological Research, China (Grant No. MMJJ201401012), the Fok Ying Tong Education Foundation, China (Grant No. 131067), and the Shandong Academy of Sciences Youth Fund Project, China (Grant No. 2013QN007).

  14. Gaussian Error Correction of Quantum States in a Correlated Noisy Channel

    DEFF Research Database (Denmark)

    Lassen, Mikael Østergaard; Berni, Adriano; Madsen, Lars Skovgaard;

    2013-01-01

    Noise is the main obstacle for the realization of fault-tolerant quantum information processing and secure communication over long distances. In this work, we propose a communication protocol relying on simple linear optics that optimally protects quantum states from non-Markovian or correlated n...

  15. Impaired information processing triggers altered states of consciousness.

    Science.gov (United States)

    Fritzsche, M

    2002-04-01

    Schizophrenia, intoxication with tetrahydrocannabinol (Delta-THC), and cannabis psychosis induce characteristic time and space distortions suggesting a common psychotic dysfunction. Since genetic research into schizophrenia has led into disappointing dead ends, the present study is focusing on this phenotype. It is shown that information theory can account for the dynamical basis of higher sensorimotor information processing and consciousness under physiologic as well as pathologic conditions. If Kolmogorov entropy (inherent in the processing of action and time) breaks down in acute psychosis, it is predicted that Shannon entropy (inherent in the processing of higher dimensional perception) will increase, provoking positive symptoms and altered states of consciousness. In the search for candidate genes and the protection of vulnerable individuals from cannabis abuse, non-linear EEG analysis of Kolmogorov information could thus present us with a novel diagnostic tool to directly assess the breakdown of information processing in schizophrenia.

  16. Vehicle State Information Estimation with the Unscented Kalman Filter

    Directory of Open Access Journals (Sweden)

    Hongbin Ren

    2014-01-01

    Full Text Available The vehicle state information plays an important role in the vehicle active safety systems; this paper proposed a new concept to estimate the instantaneous vehicle speed, yaw rate, tire forces, and tire kinemics information in real time. The estimator is based on the 3DoF vehicle model combined with the piecewise linear tire model. The estimator is realized using the unscented Kalman filter (UKF, since it is based on the unscented transfer technique and considers high order terms during the measurement and update stage. The numerical simulations are carried out to further investigate the performance of the estimator under high friction and low friction road conditions in the MATLAB/Simulink combined with the Carsim environment. The simulation results are compared with the numerical results from Carsim software, which indicate that UKF can estimate the vehicle state information accurately and in real time; the proposed estimation will provide the necessary and reliable state information to the vehicle controller in the future.

  17. The eavesdropping information in W\\'{o}jcik's scheme on ping-pong protocol in high lossy quantum channel

    CERN Document Server

    Zhang, Z J

    2004-01-01

    In this paper the relation between the mutual information and the quantum bit error rates (QBERs) is established. A simple strategy to characterize sufficiently the information gain is proposed. Various eavesdropping information and their corresponding possibilities with which the eavesdropper (Eve) gains the eavesdropping information in W\\'{o}jcik's eavesdropping scheme [Phys. Rev. Lett. {\\bf 90}, 157901(2003)] on the ping-pong protocol in a high lossy quantum channel are worked out. In addition, some mistakes in the eavesdropping scheme are pointed out.

  18. Branding and Channel Issues in E-commerce from an Information System’s Perspective

    DEFF Research Database (Denmark)

    Hansen, Rina; Tambo, Torben

    2011-01-01

    E-commerce has matured and become mainstream. The fashion industry is now competing strongly in the digital markets. Beside traditional web-shops, new sales and branding channels are emerging e.g. M-commerce (mobile); social commerce; marketplaces; gaming etc. E-commerce and multi-channel retailing...

  19. Structure of a potentially open state of a proton-activated pentameric ligand-gated ion channel.

    Science.gov (United States)

    Hilf, Ricarda J C; Dutzler, Raimund

    2009-01-01

    The X-ray structure of a pentameric ligand-gated ion channel from Erwinia chrysanthemi (ELIC) has recently provided structural insight into this family of ion channels at high resolution. The structure shows a homo-pentameric protein with a barrel-stave architecture that defines an ion-conduction pore located on the fivefold axis of symmetry. In this structure, the wide aqueous vestibule that is encircled by the extracellular ligand-binding domains of the five subunits narrows to a discontinuous pore that spans the lipid bilayer. The pore is constricted by bulky hydrophobic residues towards the extracellular side, which probably serve as barriers that prevent the diffusion of ions. This interrupted pore architecture in ELIC thus depicts a non-conducting conformation of a pentameric ligand-gated ion channel, the thermodynamically stable state in the absence of bound ligand. As ligand binding promotes pore opening in these ion channels and the specific ligand for ELIC has not yet been identified, we have turned our attention towards a homologous protein from the cyanobacterium Gloebacter violaceus (GLIC). GLIC was shown to form proton-gated channels that are activated by a pH decrease on the extracellular side and that do not desensitize after activation. Both prokaryotic proteins, ELIC and GLIC form ion channels that are selective for cations over anions with poor discrimination among monovalent cations, characteristics that resemble the conduction properties of the cation-selective branch of the family that includes acetylcholine and serotonin receptors. Here we present the X-ray structure of GLIC at 3.1 A resolution. The structure reveals a conformation of the channel that is distinct from ELIC and that probably resembles the open state. In combination, both structures suggest a novel gating mechanism for pentameric ligand-gated ion channels where channel opening proceeds by a change in the tilt of the pore-forming helices.

  20. General Framework and Advanced Information Theoretical Results on Eigenmode MIMO Channel Inversion

    Directory of Open Access Journals (Sweden)

    J. Sykora

    2005-09-01

    Full Text Available This paper provides general and deep investigation of adaptationstrategies based on the channel inversion policy regarding wide varietyof channel modes. Our novel approach to the eigenmode space MIMOchannel inversion policy relies on the eigenmode space reductionproviding zero transmission outage probability regardless of theinstantaneous channel fading realization. Very detailed survey of thefeatures of channel capacity is provided in analytical closed formexpressions supported by many particular numerical results (Alamoutischeme is included. The correlated MIMO channel is involved into ourtreatment as well. We also address the trade-off between the capacityand transmission outage probability. The novel results are developed inthe general framework with exhaustive summary of well known SISO andSIMO results.

  1. A novel mechanism for fine-tuning open-state stability in a voltage-gated potassium channel

    DEFF Research Database (Denmark)

    Pless, Stephan Alexander; Niciforovic, Ana P; Galpin, Jason D

    2013-01-01

    fluorinated derivatives of aromatic residues previously implicated in the gating of Shaker potassium channels. Here we show that stepwise dispersion of the negative electrostatic surface potential of only one site, Phe481, stabilizes the channel open state. Furthermore, these data suggest that this apparent...... stabilization is the consequence of the amelioration of an inherently repulsive open-state interaction between the partial negative charge on the face of Phe481 and a highly co-evolved acidic side chain, Glu395, and this interaction is potentially modulated through the Tyr485 hydroxyl. We propose...... that the intrinsic open-state destabilization via aromatic repulsion represents a new mechanism by which ion channels, and likely other proteins, fine-tune conformational equilibria....

  2. Chaos in quantum channels

    CERN Document Server

    Hosur, Pavan; Roberts, Daniel A; Yoshida, Beni

    2015-01-01

    We study chaos and scrambling in unitary channels by considering their entanglement properties as states. Using out-of-time-order correlation functions to diagnose chaos, we characterize the ability of a channel to process quantum information. We show that the generic decay of such correlators implies that any input subsystem must have near vanishing mutual information with almost all partitions of the output. Additionally, we propose the negativity of the tripartite information of the channel as a general diagnostic of scrambling. This measures the delocalization of information and is closely related to the decay of out-of-time-order correlators. We back up our results with numerics in two non-integrable models and analytic results in a perfect tensor network model of chaotic time evolution. These results show that the butterfly effect in quantum systems implies the information-theoretic definition of scrambling.

  3. Catalyst-like modulation of transition states for CFTR channel opening and closing: new stimulation strategy exploits nonequilibrium gating.

    Science.gov (United States)

    Csanády, László; Töröcsik, Beáta

    2014-02-01

    Cystic fibrosis transmembrane conductance regulator (CFTR) is the chloride ion channel mutated in cystic fibrosis (CF) patients. It is an ATP-binding cassette protein, and its resulting cyclic nonequilibrium gating mechanism sets it apart from most other ion channels. The most common CF mutation (ΔF508) impairs folding of CFTR but also channel gating, reducing open probability (Po). This gating defect must be addressed to effectively treat CF. Combining single-channel and macroscopic current measurements in inside-out patches, we show here that the two effects of 5-nitro-2-(3-phenylpropylamino)benzoate (NPPB) on CFTR, pore block and gating stimulation, are independent, suggesting action at distinct sites. Furthermore, detailed kinetic analysis revealed that NPPB potently increases Po, also of ΔF508 CFTR, by affecting the stability of gating transition states. This finding is unexpected, because for most ion channels, which gate at equilibrium, altering transition-state stabilities has no effect on Po; rather, agonists usually stimulate by stabilizing open states. Our results highlight how for CFTR, because of its unique cyclic mechanism, gating transition states determine Po and offer strategic targets for potentiator compounds to achieve maximal efficacy.

  4. Improving Einstein–Podolsky–Rosen steering inequalities with state information

    Energy Technology Data Exchange (ETDEWEB)

    Schneeloch, James [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Broadbent, Curtis J. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Rochester Theory Center, University of Rochester, Rochester, NY 14627 (United States); Howell, John C. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States)

    2014-02-01

    We discuss the relationship between entropic Einstein–Podolsky–Rosen (EPR)-steering inequalities and their underlying uncertainty relations along with the hypothesis that improved uncertainty relations lead to tighter EPR-steering inequalities. In particular, we discuss how using information about the state of a quantum system affects one's ability to witness EPR-steering. As an example, we consider the recent improvement to the entropic uncertainty relation between pairs of discrete observables (Berta et al., 2010 [10]). By considering the assumptions that enter into the development of a steering inequality, we derive correct steering inequalities from these improved uncertainty relations and find that they are identical to ones already developed (Schneeloch et al., 2013 [9]). In addition, we consider how one can use state information to improve our ability to witness EPR-steering, and develop a new continuous variable symmetric EPR-steering inequality as a result.

  5. Improving Einstein-Podolsky-Rosen steering inequalities with state information

    Science.gov (United States)

    Schneeloch, James; Broadbent, Curtis J.; Howell, John C.

    2014-02-01

    We discuss the relationship between entropic Einstein-Podolsky-Rosen (EPR)-steering inequalities and their underlying uncertainty relations along with the hypothesis that improved uncertainty relations lead to tighter EPR-steering inequalities. In particular, we discuss how using information about the state of a quantum system affects one's ability to witness EPR-steering. As an example, we consider the recent improvement to the entropic uncertainty relation between pairs of discrete observables (Berta et al., 2010 [10]). By considering the assumptions that enter into the development of a steering inequality, we derive correct steering inequalities from these improved uncertainty relations and find that they are identical to ones already developed (Schneeloch et al., 2013 [9]). In addition, we consider how one can use state information to improve our ability to witness EPR-steering, and develop a new continuous variable symmetric EPR-steering inequality as a result.

  6. Formal and Informal Volunteering in a State Friendly Society

    DEFF Research Database (Denmark)

    Henriksen, Lars Skov; Rosdahl, David; Koch-Nielsen, Inger

    Citizens’ civic engagement and participation in voluntary associations is shaped by several factors, some of which are institutional while others are characteristics about the individual and the environment to which s/he belongs. Based on a comprehensive population survey carried out as part of t...... of the Danish Johns Hopkins Comparative Nonprofit Sector Project, this article explores determinants of formal and informal volunteering in a ‘state friendly society’ like the Danish....

  7. Quadrature Uncertainty and Information Entropy of Quantum Elliptical Vortex States

    CERN Document Server

    Banerji, Anindya; Singh, Ravindra Pratap; Chowdhury, Saurav; Bandyopadhyay, Abir

    2013-01-01

    We study the quadrature uncertainty of the quantum elliptical vortex state using the associated Wigner function. Deviations from the minimum uncertainty states were observed due to the absence of the Gaussian nature. In our study of the entropy, we noticed that with increasing vorticity, entropy increases for both the modes. We further observed that, there exists an optimum value of ellipticity which gives rise to maximum entanglement of the two modes of the quantum elliptical vortex states. A further increase in ellipticity reduces the entropy thereby resulting in a loss of information carrying capacity. We check the validity of the entropic inequality relations, namely the subaddivity and the Araki-Lieb inequality. The later was satisfied only for a very small range of the ellipticity of the vortex while the former seemed to be valid at all values.

  8. Quantum Information Protocols with Gaussian States of Light

    DEFF Research Database (Denmark)

    Jacobsen, Christian Scheffmann

    and hardware for secure quantum key distribution. These technologies directly exploit quantum effects, and indeed this is where they offer advantages to classical products. This thesis deals with the development and implementation of quantum information protocols that utilize the rather inexpensive resource...... with Gaussian states is a promising avenue for the development of practical quantum key distribution with a relay network structure in environments where the distances are relatively short and there is a high number of users, such as an urban environment. In addition to this we consider various point......-to-point configurations that utilize Gaussian states to achieve security. Notably, we also present a novel experiment demonstrating the feasibility of delegated quantum computing on encrypted data, where we show that we can reliably encrypt and decrypt input and output states when a server with quantum computing...

  9. In the Shadow of the State - the Informal Economy and Informal Economy Labor Force

    Directory of Open Access Journals (Sweden)

    Schneider Friedrich

    2015-02-01

    Full Text Available In this paper, the main focus lies on the informal economy and on work in the shadow. The most influential factors on the informal economy are tax policies and state regulation. The size of the informal economy was decreasing over the period 1999 to 2007, from 34.0% to 31.2% for 161 countries (unweighted average. Furthermore, economic opportunities, taxes and regulations, the general situation on the labor market, and unemployment are crucial for an understanding of the dynamics of the shadow labor force. In contrast with the decrease of the informal economy (value added figures, the informal economy labor force increased for most countries over the period 1999 to 2007.

  10. Exact Performance Analysis of Partial Relay Selection Based on Shadowing Side Information over Generalized Composite Fading Channels

    CERN Document Server

    Yilmaz, Ferkan

    2011-01-01

    Relay technology has recently gained great interest in millimeter wave (60 GHz or above) radio frequencies as a promising transmission technique improving the quality of service, providing high data rate, and extending the coverage area without additional transmit power in deeply shadowed wireless environments. The performance of relay-based systems depends considerably on which relay selection protocols are used. These protocols are typically using the channel side information (CSI). Specifically, the relay terminal (RT) is chosen among all available RTs by a centralized entity (CE) which receives all RTs' CSI via feedback channels. However, in the millimeter wave radio frequencies, the rate of the variation of the CSI is much higher than that of a classical system operating in 6 GHz frequencies under the same mobility conditions, which evidently results in a serious problem causing outdated (inaccurate) CSI for the relay selection protocol at the CE since the feedback channels have a backhaul / transmission...

  11. 76 FR 588 - Comment Request for Information Collection for Workforce Information Grants to States Application...

    Science.gov (United States)

    2011-01-05

    ... flexibility, and maintain the current state reporting burden. It is ETA's goal for the Workforce Information... section of this notice. DATES: Written comments must be submitted to the office listed in the addressee's section below on or before March 7, 2011. ADDRESSES: Submit written comments to Mr. Anthony Dais, Room...

  12. Shannon information capacity of time reversal wideband multiple-input multiple-output system based on correlated statistical channels

    Science.gov (United States)

    Yu, Yang; Bing-Zhong, Wang; Shuai, Ding

    2016-05-01

    Utilizing channel reciprocity, time reversal (TR) technique increases the signal-to-noise ratio (SNR) at the receiver with very low transmitter complexity in complex multipath environment. Present research works about TR multiple-input multiple-output (MIMO) communication all focus on the system implementation and network building. The aim of this work is to analyze the influence of antenna coupling on the capacity of wideband TR MIMO system, which is a realistic question in designing a practical communication system. It turns out that antenna coupling stabilizes the capacity in a small variation range with statistical wideband channel response. Meanwhile, antenna coupling only causes a slight detriment to the channel capacity in a wideband TR MIMO system. Comparatively, uncorrelated stochastic channels without coupling exhibit a wider range of random capacity distribution which greatly depends on the statistical channel. The conclusions drawn from information difference entropy theory provide a guideline for designing better high-performance wideband TR MIMO communication systems. Project supported by the National Natural Science Foundation of China (Grant Nos. 61331007, 61361166008, and 61401065) and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120185130001).

  13. Probabilistic teleportation of an arbitrary GHZ-class state with a pure entangled two-particle quantum channel and its application in quantum state sharing

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents a scheme for probabilistic teleportation of an arbitrary GHZ-class state with a pure entangled two-particle quantum channel. The sender Alice first teleports the coefficients of the unknown state to the receiver Bob, and then Bob reconstructs the state with an auxiliary particle and some unitary operations if the teleportation succeeds. This scheme has the advantage of transmitting much less particles for teleporting an arbitrary GHZ-class state than others. Moreover, it discusses the application of this scheme in quantum state sharing.

  14. Effect of quantum noise on deterministic joint remote state preparation of a qubit state via a GHZ channel

    Science.gov (United States)

    Wang, Ming-Ming; Qu, Zhi-Guo

    2016-08-01

    Quantum secure communication brings a new direction for information security. As an important component of quantum secure communication, deterministic joint remote state preparation (DJRSP) could securely transmit a quantum state with 100 % success probability. In this paper, we study how the efficiency of DJRSP is affected when qubits involved in the protocol are subjected to noise or decoherence. Taking a GHZ-based DJRSP scheme as an example, we study all types of noise usually encountered in real-world implementations of quantum communication protocols, i.e., the bit-flip, phase-flip (phase-damping), depolarizing and amplitude-damping noise. Our study shows that the fidelity of the output state depends on the phase factor, the amplitude factor and the noise parameter in the bit-flip noise, while the fidelity only depends on the amplitude factor and the noise parameter in the other three types of noise. And the receiver will get different output states depending on the first preparer's measurement result in the amplitude-damping noise. Our results will be helpful for improving quantum secure communication in real implementation.

  15. Effect of quantum noise on deterministic joint remote state preparation of a qubit state via a GHZ channel

    Science.gov (United States)

    Wang, Ming-Ming; Qu, Zhi-Guo

    2016-11-01

    Quantum secure communication brings a new direction for information security. As an important component of quantum secure communication, deterministic joint remote state preparation (DJRSP) could securely transmit a quantum state with 100 % success probability. In this paper, we study how the efficiency of DJRSP is affected when qubits involved in the protocol are subjected to noise or decoherence. Taking a GHZ-based DJRSP scheme as an example, we study all types of noise usually encountered in real-world implementations of quantum communication protocols, i.e., the bit-flip, phase-flip (phase-damping), depolarizing and amplitude-damping noise. Our study shows that the fidelity of the output state depends on the phase factor, the amplitude factor and the noise parameter in the bit-flip noise, while the fidelity only depends on the amplitude factor and the noise parameter in the other three types of noise. And the receiver will get different output states depending on the first preparer's measurement result in the amplitude-damping noise. Our results will be helpful for improving quantum secure communication in real implementation.

  16. State Bioenergy Primer: Information and Resources for States on Issues, Opportunities, and Options for Advancing Bioenergy

    Energy Technology Data Exchange (ETDEWEB)

    Byrnett, D. S.; Mulholland, D.; Zinsmeister, E.; Doris, E.; Milbrandt, A.; Robichaud. R.; Stanley, R.; Vimmerstedt, L.

    2009-09-01

    One renewable energy option that states frequently consider to meet their clean energy goals is the use of biomass resources to develop bioenergy. Bioenergy includes bioheat, biopower, biofuels, and bioproducts. This document provides an overview of biomass feedstocks, basic information about biomass conversion technologies, and a discussion of benefits and challenges of bioenergy options. The Primer includes a step-wise framework, resources, and tools for determining the availability of feedstocks, assessing potential markets for biomass, and identifying opportunities for action at the state level. Each chapter contains a list of selected resources and tools that states can use to explore topics in further detail.

  17. The role of patient-clinician information engagement and information seeking from nonmedical channels in fruit and vegetable intake among cancer patients.

    Science.gov (United States)

    Moldovan-Johnson, Mihaela; Martinez, Lourdes; Lewis, Nehama; Freres, Derek; Hornik, Robert C

    2014-12-01

    Previous research suggests positive effects of health information seeking on prevention behaviors such as diet, exercise, and fruit and vegetable consumption. The present study builds upon this research and strengthens causal claims from it by examining the lagged effect of patient-clinician information engagement on fruit and vegetable consumption as well as the indirect effect on the outcome through seeking information from nonmedical channels. The results are based on data collected from a randomly drawn sample of breast, prostate, and colorectal cancer patients from the Pennsylvania Cancer Registry who completed mail surveys in the Fall of 2006 and 2007. There was a 65% response rate for baseline subjects (resulting n = 2,013); of those, 1,293 were interviewed 1 year later, and 1,257 were available for our analyses. Results show a positive lagged main effect of patient-clinician information engagement at baseline on fruit and vegetable consumption at follow-up (B = 0.26, SE = 0.10, p = .01). The mediation analysis shows that patient-clinician information engagement leads to increased fruit and vegetable consumption among cancer patients, in part through patients' information seeking from nonmedical channels. Implications of these findings for the cancer patient population and for physicians are discussed.

  18. Information complementarity in multipartite quantum states and security in cryptography

    Science.gov (United States)

    Bera, Anindita; Kumar, Asutosh; Rakshit, Debraj; Prabhu, R.; SenDe, Aditi; Sen, Ujjwal

    2016-03-01

    We derive complementarity relations for arbitrary quantum states of multiparty systems of any number of parties and dimensions between the purity of a part of the system and several correlation quantities, including entanglement and other quantum correlations as well as classical and total correlations, of that part with the remainder of the system. We subsequently use such a complementarity relation between purity and quantum mutual information in the tripartite scenario to provide a bound on the secret key rate for individual attacks on a quantum key distribution protocol.

  19. State-Dependent Resource Harvesting with Lagged Information about System States.

    Directory of Open Access Journals (Sweden)

    Fred A Johnson

    Full Text Available Markov decision processes (MDPs, which involve a temporal sequence of actions conditioned on the state of the managed system, are increasingly being applied in natural resource management. This study focuses on the modification of a traditional MDP to account for those cases in which an action must be chosen after a significant time lag in observing system state, but just prior to a new observation. In order to calculate an optimal decision policy under these conditions, possible actions must be conditioned on the previous observed system state and action taken. We show how to solve these problems when the state transition structure is known and when it is uncertain. Our focus is on the latter case, and we show how actions must be conditioned not only on the previous system state and action, but on the probabilities associated with alternative models of system dynamics. To demonstrate this framework, we calculated and simulated optimal, adaptive policies for MDPs with lagged states for the problem of deciding annual harvest regulations for mallards (Anas platyrhynchos in the United States. In this particular example, changes in harvest policy induced by the use of lagged information about system state were sufficient to maintain expected management performance (e.g. population size, harvest even in the face of an uncertain system state at the time of a decision.

  20. State-dependent resource harvesting with lagged information about system states

    Science.gov (United States)

    Johnson, Fred A.; Fackler, Paul L.; Boomer, G Scott; Zimmerman, Guthrie; Williams, Byron K.; Nichols, James; Dorazio, Robert

    2016-01-01

    Markov decision processes (MDPs), which involve a temporal sequence of actions conditioned on the state of the managed system, are increasingly being applied in natural resource management. This study focuses on the modification of a traditional MDP to account for those cases in which an action must be chosen after a significant time lag in observing system state, but just prior to a new observation. In order to calculate an optimal decision policy under these conditions, possible actions must be conditioned on the previous observed system state and action taken. We show how to solve these problems when the state transition structure is known and when it is uncertain. Our focus is on the latter case, and we show how actions must be conditioned not only on the previous system state and action, but on the probabilities associated with alternative models of system dynamics. To demonstrate this framework, we calculated and simulated optimal, adaptive policies for MDPs with lagged states for the problem of deciding annual harvest regulations for mallards (Anas platyrhynchos) in the United States. In this particular example, changes in harvest policy induced by the use of lagged information about system state were sufficient to maintain expected management performance (e.g. population size, harvest) even in the face of an uncertain system state at the time of a decision.

  1. Analysis of the secrecy of the running key in quantum encryption channels using coherent states of light

    Science.gov (United States)

    Nikulin, Vladimir V.; Hughes, David H.; Malowicki, John; Bedi, Vijit

    2015-05-01

    Free-space optical communication channels offer secure links with low probability of interception and detection. Despite their point-to-point topology, additional security features may be required in privacy-critical applications. Encryption can be achieved at the physical layer by using quantized values of photons, which makes exploitation of such quantum communication links extremely difficult. One example of such technology is keyed communication in quantum noise, a novel quantum modulation protocol that offers ultra-secure communication with competitive performance characteristics. Its utilization relies on specific coherent measurements to decrypt the signal. The process of measurements is complicated by the inherent and irreducible quantum noise of coherent states. This problem is different from traditional laser communication with coherent detection; therefore continuous efforts are being made to improve the measurement techniques. Quantum-based encryption systems that use the phase of the signal as the information carrier impose aggressive requirements on the accuracy of the measurements when an unauthorized party attempts intercepting the data stream. Therefore, analysis of the secrecy of the data becomes extremely important. In this paper, we present the results of a study that had a goal of assessment of potential vulnerability of the running key. Basic results of the laboratory measurements are combined with simulation studies and statistical analysis that can be used for both conceptual improvement of the encryption approach and for quantitative comparison of secrecy of different quantum communication protocols.

  2. Lacosamide Inhibition of Nav1.7 Voltage-Gated Sodium Channels: Slow Binding to Fast-Inactivated States.

    Science.gov (United States)

    Jo, Sooyeon; Bean, Bruce P

    2017-04-01

    Lacosamide is an antiseizure agent that targets voltage-dependent sodium channels. Previous experiments have suggested that lacosamide is unusual in binding selectively to the slow-inactivated state of sodium channels, in contrast to drugs like carbamazepine and phenytoin, which bind tightly to fast-inactivated states. Using heterologously expressed human Nav1.7 sodium channels, we examined the state-dependent effects of lacosamide. Lacosamide induced a reversible shift in the voltage dependence of fast inactivation studied with 100-millisecond prepulses, suggesting binding to fast-inactivated states. Using steady holding potentials, lacosamide block was very weak at -120 mV (3% inhibition by 100 µM lacosamide) but greatly enhanced at -80 mV (43% inhibition by 100 µM lacosamide), where there is partial fast inactivation but little or no slow inactivation. During long depolarizations, lacosamide slowly (over seconds) put channels into states that recovered availability slowly (hundreds of milliseconds) at -120 mV. This resembles enhancement of slow inactivation, but the effect was much more pronounced at -40 mV, where fast inactivation is complete, but slow inactivation is not, than at 0 mV, where slow inactivation is maximal, more consistent with slow binding to fast-inactivated states than selective binding to slow-inactivated states. Furthermore, inhibition by lacosamide was greatly reduced by pretreatment with 300 µM lidocaine or 300 µM carbamazepine, suggesting that lacosamide, lidocaine, and carbamazepine all bind to the same site. The results suggest that lacosamide binds to fast-inactivated states in a manner similar to other antiseizure agents but with slower kinetics of binding and unbinding.

  3. Search for narrow pion-proton states in s-channel at EPECUR: experiment status

    CERN Document Server

    Alekseev, I G; Bordyuzhin, I G; Budkovsky, P Ye; Fedin, D A; Filimonov, Ye A; Golubev, V V; Kanavets, V P; Koroleva, L I; Kovalev, A I; Kozlenko, N G; Kozlov, V S; Krivshich, A G; Morozov, B V; Nesterov, V M; Novinsky, D V; Ryltsov, V V; Sadler, M; Sulimov, A D; Sumachev, V V; Svirida, D N; Tarakanov, V I; Trautman, V Yu

    2009-01-01

    An experiment EPECUR, aimed at the search of the cryptoexotic non-strange member of the pentaquark antidecuplet, started its operation at a pion beam line of the ITEP 10 GeV proton synchrotron. The invariant mass range of the interest (1610-1770) MeV will be scanned for a narrow state in the pion-proton and kaon-lambda systems in the formation-type experiment. The scan in the s-channel is supposed to be done by the variation of the incident pi- momentum and its measurement with the accuracy of up to 0.1% with a set of 1 mm pitch proportional chambers located in the first focus of the beam line. The reactions under the study will be identified by a magnetless spectrometer based on wire drift chambers with a hexagonal structure. Because the background suppression in this experiment depends on the angular resolution, the amount of matter in the chambers and setup is minimized to reduce multiple scattering. The differential cross section of the elastic pi-p-scattering on a liquid hydrogen target in the region of ...

  4. Coupled channel Faddeev calculations of a K-bar N{pi} quasibound state

    Energy Technology Data Exchange (ETDEWEB)

    Gal, A., E-mail: avragal@vms.huji.ac.il [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Garcilazo, H., E-mail: humberto@esfm.ipn.mx [Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional, Edificio 9, 07738 Mexico D.F. (Mexico)

    2011-08-01

    The K-bar N{pi} system is studied using separable interactions fitted to data available on the s-wave K-bar N-{pi}Y subsystem and the p-wave {pi}N, {pi}Y, {pi}{pi} and {pi}K-bar subsystems. Three-body K-bar N{pi}-{pi}Y{pi} coupled channel Faddeev equations with relativistic kinematics are solved in search for poles in the complex energy plane. A K-bar N{pi} quasibound pole with quantum numbers I(J{sup P})=1(3/2{sup -}) is found near and below the K-bar N{pi} threshold, its precise location depending sensitively on the poorly known shape of the p-wave {pi}Y interaction. This K-bar N{pi} quasibound state suggests the existence of a D{sub 13{Sigma}} resonance with width about 60 MeV near threshold (M{approx}1570 MeV), excluding meson absorption contributions.

  5. A collective coupled-channel model and mirror state energy displacements

    Science.gov (United States)

    Fraser, P. R.; Amos, K.; Canton, L.; Karataglidis, S.; van der Knijff, D.; Svenne, J. P.

    2015-09-01

    The spectra of nucleon-nucleus mirror systems allow examination of charge symmetry breaking in nucleon-nucleus interactions. To date, such examination has been performed with studies using microscopic models of structure. Herein we seek characterisation with a coupled-channel model in which the nucleon-nucleus interactions are described using a collective model prescription with the Pauli principle taken into account. The neutron-nucleus Hamiltonian is chosen to give the best match to the compound system spectrum, with emphasis on finding the correct ground state energy relative to the neutron-nucleus threshold. The Coulomb interactions for the proton-nucleus partner of a mirror pair are determined using charge distributions that match the root-mean-square charge radii of the nuclei in question. With the Coulomb interaction so defined modifying the neutron-nucleus Hamiltonian, we then predict a spectrum for the relevant proton-nucleus compound. Discrepancies in that resulting spectrum with measured values we tentatively ascribe to charge-symmetry breaking effects. We consider spectra obtained in this way for the mirror pairs 13C and 13N, 15C and 15F, and 15O and 15N, all to ˜ 10 MeV excitation.

  6. The s-channel charged Higgs in the fully hadronic final state at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Ijaz [University of Malaya, National Center for Particle Physics, Kuala Lumpur (Malaysia); COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Hashemi, Majid [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Tajuddin, Wan Ahmad [University of Malaya, National Center for Particle Physics, Kuala Lumpur (Malaysia)

    2016-04-15

    With the current measurements performed by CMS and ATLAS experiments, the light charged Higgs scenario (m{sub H}{sup {sub ±}} < 160 GeV), is excluded for most of the parameter space in the context of MSSM. However, there is still possibility to look for heavy charged Higgs boson particularly in the s-channel single top production process where the charged Higgs may appear as a heavy resonance state and decay to t anti b. The production process under consideration in this paper is pp → H{sup ±} → t anti b + h.c., where the top quark decays to W{sup +}b and W{sup +} boson subsequently decays to two light jets. It is shown that despite the presence of large QCD and electroweak background events, the charged Higgs signal can be extracted and observed at a large area of MSSM parameter space (m{sub H}{sup {sub ±}}, tanβ) at LHC. The observability of charged Higgs is potentially demonstrated with 5σ contours and 95% confidence level exclusion curves at different integrated LHC luminosities assuming a nominal center of mass energy of √(s) = 14 TeV. (orig.)

  7. Network Intelligence Based on Network State Information for Connected Vehicles Utilizing Fog Computing

    Directory of Open Access Journals (Sweden)

    Seongjin Park

    2017-01-01

    Full Text Available This paper proposes a method to take advantage of fog computing and SDN in the connected vehicle environment, where communication channels are unstable and the topology changes frequently. A controller knows the current state of the network by maintaining the most recent network topology. Of all the information collected by the controller in the mobile environment, node mobility information is particularly important. Thus, we divide nodes into three classes according to their mobility types and use their related attributes to efficiently manage the mobile connections. Our approach utilizes mobility information to reduce control message overhead by adjusting the period of beacon messages and to support efficient failure recovery. One is to recover the connection failures using only mobility information, and the other is to suggest a real-time scheduling algorithm to recover the services for the vehicles that lost connection in the case of a fog server failure. A real-time scheduling method is first described and then evaluated. The results show that our scheme is effective in the connected vehicle environment. We then demonstrate the reduction of control overhead and the connection recovery by using a network simulator. The simulation results show that control message overhead and failure recovery time are decreased by approximately 55% and 5%, respectively.

  8. MIMO Interference Alignment Over Correlated Channels with Imperfect CSI

    CERN Document Server

    Nosrat-Makouei, Behrang; Heath, Robert W

    2010-01-01

    Interference alignment (IA), given uncorrelated channel components and perfect channel state information, obtains the maximum degrees of freedom in an interference channel. Little is known, however, about how the sum rate of IA behaves at finite transmit power, with imperfect channel state information, or antenna correlation. This paper provides an approximate closed-form signal-to-interference-plus-noise-ratio (SINR) expression for IA over multiple-input-multiple-output (MIMO) channels with imperfect channel state information and transmit antenna correlation. Assuming linear processing at the transmitters and zero-forcing receivers, random matrix theory tools are utilized to derive an approximation for the post-processing SINR distribution of each stream for each user. Perfect channel knowledge and i.i.d. channel coefficients constitute special cases. This SINR distribution not only allows easy calculation of useful performance metrics like sum rate and symbol error rate, but also permits a realistic compari...

  9. DETERMINANTS OF THE CHOICE OF MARKETING CHANNELS BY CORPORATE CLIENTS: AN ANALYSIS OF THE INFORMATION TECHNOLOGY SECTOR

    Directory of Open Access Journals (Sweden)

    Guilherme Soares

    2012-12-01

    Full Text Available Based on a survey of 505 corporate clients from the information technology industry, this study uses a logit statistical model to analyze whether such factors as loyalty, trust, client importance, intimacy between customer and supplier and the cost of changing suppliers may affect the choice of the marketing channel used by the client. The results show that the greater intimacy between a supplier and a corporate client is a determining factor for the client’s preference for being served by the manufacturer rather than an intermediary. In contrast, clients’ perception of their own importance to the supplier is not very relevant to their preference for being served directly by the manufacturer, and the other factors were not identified as (statistically important determinants of the choice of the marketing channel. These results suggest that the real advantage of the direct sales channel over the indirect sales channel lies in its ability to strengthen the client-manufacturer relationship, thereby contributing to the development of solutions that better serve the needs of corporate clients.

  10. Copper link evaluations/solutions for fiber channel, SSA, SONET, ATM, and other services through 4 Gb/sec: basic information, test results, and evaluation

    Science.gov (United States)

    Leib, Michael J.

    1995-10-01

    Technitrol, the original designer of MIL-STD-1553 transformers, the original military 1Mb/s LAN, has advanced the state of the art one further notch, introducing a series of transceivers that allow high speed (through 1 Gb/s) data transmission over copper wire instead of fiber optic cable. One such device can be employed to implement the Fiber Channel Interface as defined by hte X3T11 ANSI Fibre Channel Committee using either mini coax, Type 1 shielded twisted pair, twinax or video cable. The technology now exists to upgrade data transmission rates on current physical media to speeds formerly only available with fiber optic cabling. Copper transceiver technology provides a cost effective alternative for dealing with demanding high speed applications such as high speed serial data transfer, high speed disk and tape storage transfer, imaging telemetry, radar, and other avionics applications. Eye diagrams will be presented to show that excellent data transmission at rates of 1 gigabit/sec with low jitter is capable over mini coax at distances to approximately 50 meters, shielded twisted pair and twinax cable to distances of 105 meters, and video cable to distances of 175 meters. Distances are further at lower data rates. As a member of the X3T11 ANSI Fiber Channel Committee, Technitrol has developed a Physical Media (copper wire) Dependant (PMD) transceiver not only compliant with the Fibre Channel Specifications but exceeding the specifications by a factor greater than four. Conceivably, this opens high speed interconnections for today's high data rate requirements to copper cabling systems. Fibre Optic problems need not be dealt with to obtain data transfers for high speed information transfers.

  11. 76 FR 43701 - Renewal of Agency Information Collection for Class III Tribal State Gaming Compact Process...

    Science.gov (United States)

    2011-07-21

    ... Bureau of Indian Affairs Renewal of Agency Information Collection for Class III Tribal State Gaming... the collection of information for the Class III Tribal State Gaming Compact Process. The information... for the information collection conducted under 25 CFR 293, Class III Tribal State Gaming...

  12. On the Present State of Information Society Studies.

    Science.gov (United States)

    Duff, Alistair S.

    2001-01-01

    Assesses the present condition of the emerging specialism of information society studies. Topics include the information economy; information technology; the information explosion; the Japanese version of information society; information society as social democracy; sociology and information science; scholarly journals; and the need for…

  13. Finite-Time Distributed State Estimation Over Sensor Networks With Round-Robin Protocol and Fading Channels.

    Science.gov (United States)

    Xu, Yong; Lu, Renquan; Shi, Peng; Li, Hongyi; Xie, Shengli

    2016-12-15

    This paper considers finite-time distributed state estimation for discrete-time nonlinear systems over sensor networks. The Round-Robin protocol is introduced to overcome the channel capacity constraint among sensor nodes, and the multiplicative noise is employed to model the channel fading. In order to improve the performance of the estimator under the situation, where the transmission resources are limited, fading channels with different stochastic properties are used in each round by allocating the resources. Sufficient conditions of the average stochastic finite-time boundedness and the average stochastic finite-time stability for the estimation error system are derived on the basis of the periodic system analysis method and Lyapunov approach, respectively. According to the linear matrix inequality approach, the estimator gains are designed. Finally, the effectiveness of the developed results are illustrated by a numerical example.

  14. The ladder-shaped polyether toxin gambierol anchors the gating machinery of Kv3.1 channels in the resting state.

    Science.gov (United States)

    Kopljar, Ivan; Labro, Alain J; de Block, Tessa; Rainier, Jon D; Tytgat, Jan; Snyders, Dirk J

    2013-03-01

    Voltage-gated potassium (Kv) and sodium (Nav) channels are key determinants of cellular excitability and serve as targets of neurotoxins. Most marine ciguatoxins potentiate Nav channels and cause ciguatera seafood poisoning. Several ciguatoxins have also been shown to affect Kv channels, and we showed previously that the ladder-shaped polyether toxin gambierol is a potent Kv channel inhibitor. Most likely, gambierol acts via a lipid-exposed binding site, located outside the K(+) permeation pathway. However, the mechanism by which gambierol inhibits Kv channels remained unknown. Using gating and ionic current analysis to investigate how gambierol affected S6 gate opening and voltage-sensing domain (VSD) movements, we show that the resting (closed) channel conformation forms the high-affinity state for gambierol. The voltage dependence of activation was shifted by >120 mV in the depolarizing direction, precluding channel opening in the physiological voltage range. The (early) transitions between the resting and the open state were monitored with gating currents, and provided evidence that strong depolarizations allowed VSD movement up to the activated-not-open state. However, for transition to the fully open (ion-conducting) state, the toxin first needed to dissociate. These dissociation kinetics were markedly accelerated in the activated-not-open state, presumably because this state displayed a much lower affinity for gambierol. A tetrameric concatemer with only one high-affinity binding site still displayed high toxin sensitivity, suggesting that interaction with a single binding site prevented the concerted step required for channel opening. We propose a mechanism whereby gambierol anchors the channel's gating machinery in the resting state, requiring more work from the VSD to open the channel. This mechanism is quite different from the action of classical gating modifier peptides (e.g., hanatoxin). Therefore, polyether toxins open new opportunities in structure

  15. Quantum information analysis of electronic states at different molecular structures

    CERN Document Server

    Barcza, G; Marti, K H; Reiher, M

    2010-01-01

    We have studied transition metal clusters from a quantum information theory perspective using the density-matrix renormalization group (DMRG) method. We demonstrate the competition between entanglement and interaction localization. We also discuss the application of the configuration interaction based dynamically extended active space procedure which significantly reduces the effective system size and accelerates the speed of convergence for complicated molecular electronic structures to a great extent. Our results indicate the importance of taking entanglement among molecular orbitals into account in order to devise an optimal orbital ordering and carry out efficient calculations on transition metal clusters. We propose a recipe to perform DMRG calculations in a black-box fashion and we point out the connections of our work to other tensor network state approaches.

  16. 45 CFR 150.205 - Sources of information triggering an investigation of State enforcement.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Sources of information triggering an investigation... § 150.205 Sources of information triggering an investigation of State enforcement. Information that may... complaint received by CMS. (b) Information learned during informal contact between CMS and State...

  17. The surface accessibility of the glycine receptor M2-M3 loop is increased in the channel open state.

    Science.gov (United States)

    Lynch, J W; Han, N L; Haddrill, J; Pierce, K D; Schofield, P R

    2001-04-15

    Mutations in the extracellular M2-M3 loop of the glycine receptor (GlyR) alpha1 subunit have been shown previously to affect channel gating. In this study, the substituted cysteine accessibility method was used to investigate whether a structural rearrangement of the M2-M3 loop accompanies GlyR activation. All residues from R271C to V277C were covalently modified by both positively charged methanethiosulfonate ethyltrimethylammonium (MTSET) and negatively charged methanethiosulfonate ethylsulfonate (MTSES), implying that these residues form an irregular surface loop. The MTSET modification rate of all residues from R271C to K276C was faster in the glycine-bound state than in the unliganded state. MTSES modification of A272C, L274C, and V277C was also faster in the glycine-bound state. These results demonstrate that the surface accessibility of the M2-M3 loop is increased as the channel transitions from the closed to the open state, implying that either the loop itself or an overlying domain moves during channel activation.

  18. S3-S4 linker length modulates the relaxed state of a voltage-gated potassium channel.

    Science.gov (United States)

    Priest, Michael F; Lacroix, Jérôme J; Villalba-Galea, Carlos A; Bezanilla, Francisco

    2013-11-19

    Voltage-sensing domains (VSDs) are membrane protein modules found in ion channels and enzymes that are responsible for a large number of fundamental biological tasks, such as neuronal electrical activity. The VSDs switch from a resting to an active conformation upon membrane depolarization, altering the activity of the protein in response to voltage changes. Interestingly, numerous studies describe the existence of a third distinct state, called the relaxed state, also populated at positive potentials. Although some physiological roles for the relaxed state have been suggested, little is known about the molecular determinants responsible for the development and modulation of VSD relaxation. Several lines of evidence have suggested that the linker (S3-S4 linker) between the third (S3) and fourth (S4) transmembrane segments of the VSD alters the equilibrium between resting and active conformations. By measuring gating currents from the Shaker potassium channel, we demonstrate here that shortening the S3-S4 linker stabilizes the relaxed state, whereas lengthening the linker or splitting it and coinjecting two fragments of the channel have little effect. We propose that natural variations of the length of the S3-S4 linker in various VSD-containing proteins may produce differential VSD relaxation in vivo.

  19. Educational Approach to Information Transmission Channels of Data from Two Different Viewpoints: Combinatorial and Probabilistic

    OpenAIRE

    Silviu Draghici; Cornelia Victoria Anghel Drugarin; Andrea Amalia Minda; Mihaela Raduca; Eugen Raduca

    2014-01-01

    For future engineers is important to know how to make the transfer of information, data and tasks between different systems and thus we can say that the problem of communication is as important as the determination of the amount of information. Elements of information theory and communications are useful to all students of the electrical engineering specializations who must be able to collect, store, process and interpret information of any kind. In order to determine the ...

  20. Health information: a case of saturation or 57 channels and nothing on?

    Science.gov (United States)

    Whitelaw, Sandy

    2008-07-01

    The claim is made by many that we have reached a point where we are exposed to too much information. This potential phenomenon is particularly prominent in the health field where there is a suggestion that the volume of available information has increased significantly and more importantly that such volume has had detrimental effects on both the overall quality of such information and the ability of people to process and use it. This paper explores the nature and validity of these claims. Within the context of the notion of an 'information society', it outlines a range of concerns that have been expressed in relation to this increase, including the simple problem of overload, the potential for less robust information to enter the system and thus the overall quality of available information to decline. This excess of information is seen to act against the benefits that are sought--information can be invalid and people may not have time to reflect and act on excessive information loads. This can result in irrationality or disinformation. The suggestion is made, however, that these concerns are largely unsupported by empirical evidence and are potentially the basis of a panic over the entry of alternative perspectives on health. The pessimistic perspectives are thus balanced by more constructive and optimistic views on this growth and opening up of information production and potential consumption. Seeing information creation as organic and pluralistic, it is suggested that increased information volume can actually be a constructive phenomenon. The paper concludes with the contention that it is unrealistic to expect a return to former circumstances of controlled and limited information flows. Rather, a series of more pragmatic suggestions is offered within existing circumstances, including differentiating between information rich and poor health areas, addressing structural issues like information access and health literacy, and working towards organizing health

  1. Transceiver Pair Designs for Multiple Access Channels under Fixed Sum Mutual Information using MMSE Decision Feedback Detection

    CERN Document Server

    Jiang, Wenwen; Wong, Kon Max

    2008-01-01

    In this paper, we consider the joint design of the transceivers for a multiple access Multiple Input and Multiple Output (MIMO) system having Inter-Symbol Interference (ISI) channels. The system we consider is equipped with the Minimum Mean Square Error (MMSE) Decision-Feedback (DF) detector. Traditionally, transmitter designs for this system have been based on constraints of either the transmission power or the signal-to-interference-and-noise ratio (SINR) for each user. Here, we explore a novel perspective and examine a transceiver design which is based on a fixed sum mutual information constraint and minimizes the arithmetic average of mean square error of MMSE-decision feedback detection. For this optimization problem, a closed-form solution is obtained and is achieved if and only if the averaged sum mutual information is uniformly distributed over each active subchannel. Meanwhile, the mutual information of the currently detected user is uniformly distributed over each individual symbol within the block ...

  2. Compressive Sensing With Prior Support Quality Information and Application to Massive MIMO Channel Estimation With Temporal Correlation

    Science.gov (United States)

    Rao, Xiongbin; Lau, Vincent K. N.

    2015-09-01

    In this paper, we consider the problem of compressive sensing (CS) recovery with a prior support and the prior support quality information available. Different from classical works which exploit prior support blindly, we shall propose novel CS recovery algorithms to exploit the prior support adaptively based on the quality information. We analyze the distortion bound of the recovered signal from the proposed algorithm and we show that a better quality prior support can lead to better CS recovery performance. We also show that the proposed algorithm would converge in $\\mathcal{O}\\left(\\log\\mbox{SNR}\\right)$ steps. To tolerate possible model mismatch, we further propose some robustness designs to combat incorrect prior support quality information. Finally, we apply the proposed framework to sparse channel estimation in massive MIMO systems with temporal correlation to further reduce the required pilot training overhead.

  3. The role of dissociation channels of excited electronic states in quantum optimal control of ozone isomerization: A three-state dynamical model

    Science.gov (United States)

    Kurosaki, Yuzuru; Ho, Tak-San; Rabitz, Herschel

    2016-05-01

    The prospect of performing the open → cyclic ozone isomerization has attracted much research attention. Here we explore this consideration theoretically by performing quantum optimal control calculations to demonstrate the important role that excited-state dissociation channels could play in the isomerization transformation. In the calculations we use a three-state, one-dimensional dynamical model constructed from the lowest five 1A‧ potential energy curves obtained with high-level ab initio calculations. Besides the laser field-dipole couplings between all three states, this model also includes the diabatic coupling between the two excited states at an avoided crossing leading to competing dissociation channels that can further hinder the isomerization process. The present three-state optimal control simulations examine two possible control pathways previously considered in a two-state model, and reveal that only one of the pathways is viable, achieving a robust ∼95% yield to the cyclic target in the three-state model. This work represents a step towards an ultimate model for the open → cyclic ozone transformation capable of giving adequate guidance about the necessary experimental control field resources as well as an estimate of the ro-vibronic spectral character of cyclic ozone as a basis for an appropriate probe of its formation.

  4. Pre-trip tourism information search by smartphones and use of alternative information channels: A conceptual model

    Directory of Open Access Journals (Sweden)

    Chaang-Iuan Ho

    2016-12-01

    Full Text Available This study developed a comprehensive model of how smartphone users search for pre-trip tourism information. Important dimensions and relationships in tourism information search (TIS behavior were studied in 21 subjects. The data collection process included semi-structured in-depth interviewing data and field observation data. The analysis revealed 10 activities characteristic of TIS behavior: internal searches, mobile searches, saving information in the smartphones, preliminary collaborative TIS, barriers to TIS, bringing mobile search to an end, summarizing information, PC Internet search, advanced collaborative TIS, and searches via editorial communications. Such data collection was not performed in isolation. Further, 20 propositions have been developed for future testing. The results suggest that pre-trip TIS appears to consist in a diversity of search patterns with the usage of multiple information sources; in addition, it is no longer individual but collaborative behavior in the context of Web 2.0. Finally, the theoretical and practical implications of the research work are discussed, and directions for future work are suggested.

  5. 78 FR 75959 - Agency Information Collection (Regulation on Reduction of Nursing Shortages in State Homes...

    Science.gov (United States)

    2013-12-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Agency Information Collection (Regulation on Reduction of Nursing Shortages in State Homes....'' SUPPLEMENTARY INFORMATION: Title: Regulation on Reduction of Nursing Shortages in State Homes; Application...

  6. Simple, fast and accurate implementation of the diffusion approximation algorithm for stochastic ion channels with multiple states.

    Directory of Open Access Journals (Sweden)

    Patricio Orio

    Full Text Available BACKGROUND: The phenomena that emerge from the interaction of the stochastic opening and closing of ion channels (channel noise with the non-linear neural dynamics are essential to our understanding of the operation of the nervous system. The effects that channel noise can have on neural dynamics are generally studied using numerical simulations of stochastic models. Algorithms based on discrete Markov Chains (MC seem to be the most reliable and trustworthy, but even optimized algorithms come with a non-negligible computational cost. Diffusion Approximation (DA methods use Stochastic Differential Equations (SDE to approximate the behavior of a number of MCs, considerably speeding up simulation times. However, model comparisons have suggested that DA methods did not lead to the same results as in MC modeling in terms of channel noise statistics and effects on excitability. Recently, it was shown that the difference arose because MCs were modeled with coupled gating particles, while the DA was modeled using uncoupled gating particles. Implementations of DA with coupled particles, in the context of a specific kinetic scheme, yielded similar results to MC. However, it remained unclear how to generalize these implementations to different kinetic schemes, or whether they were faster than MC algorithms. Additionally, a steady state approximation was used for the stochastic terms, which, as we show here, can introduce significant inaccuracies. MAIN CONTRIBUTIONS: We derived the SDE explicitly for any given ion channel kinetic scheme. The resulting generic equations were surprisingly simple and interpretable--allowing an easy, transparent and efficient DA implementation, avoiding unnecessary approximations. The algorithm was tested in a voltage clamp simulation and in two different current clamp simulations, yielding the same results as MC modeling. Also, the simulation efficiency of this DA method demonstrated considerable superiority over MC methods

  7. Majorana bound states in two-channel time-reversal-symmetric nanowire systems.

    Science.gov (United States)

    Gaidamauskas, Erikas; Paaske, Jens; Flensberg, Karsten

    2014-03-28

    We consider time-reversal-symmetric two-channel semiconducting quantum wires proximity coupled to a conventional s-wave superconductor. We analyze the requirements for a nontrivial topological phase and find that the necessary conditions are (1) the determinant of the pairing matrix in channel space must be negative, (2) inversion symmetry must be broken, and (3) the two channels must have different spin-orbit couplings. The first condition can be implemented in semiconducting nanowire systems where interactions suppress intra-channel pairing, while the inversion symmetry can be broken by tuning the chemical potentials of the channels. For the case of collinear spin-orbit directions, we find a general expression for the topological invariant by block diagonalization into two blocks with chiral symmetry only. By projection to the low-energy sector, we solve for the zero modes explicitly and study the details of the gap closing, which in the general case happens at finite momenta.

  8. The flood, the channels, and the dykes : managing legal information a globalized and digital world

    OpenAIRE

    Breuker, Joost; Casanovas, Pompeu; Klein, Michel C. A.; Francesconi, Enrico

    2009-01-01

    Information search and retrieval are part of daily routines of the legal profession. Lawyers, judges, prosecutors, and legal clerks usually access a number of electronic resources to browse, search, select, or update legal contents. Legal databases have currently become large digital libraries where the tasks related to information-seeking may sometimes be cumbersome. Adding semantics to support information search may provide significant results in terms of efficiency, efficacy, and user sati...

  9. 78 FR 53478 - Proposed Information Collection; United States Park Police Personal History Statement

    Science.gov (United States)

    2013-08-29

    ... National Park Service Proposed Information Collection; United States Park Police Personal History Statement... information about this IC, contact Major Scott Fear, United States Park Police, 1100 Ohio Drive SW...). SUPPLEMENTARY INFORMATION: I. Abstract The United States Park Police (USPP) is a unit of the National...

  10. Deterministic distribution of four-photon Dicke state over an arbitrary collective-noise channel with cross-Kerr nonlinearity

    Science.gov (United States)

    Wang, Mei-Yu; Yan, Feng-Li; Gao, Ting

    2016-07-01

    We present two deterministic quantum entanglement distribution protocols for a four-photon Dicke polarization entangled state resorting to the frequency and spatial degrees of freedom, which are immune to an arbitrary collective-noise channel. Both of the protocols adopt the X homodyne measurement based on the cross-Kerr nonlinearity to complete the task of the single-photon detection with nearly unit probability in principle. After the four receivers share the photons, they add some local unitary operations to obtain a standard four-photon Dicke polarization entangled state.

  11. Crowdsourcing, Citizen Science or Volunteered Geographic Information? The Current State of Crowdsourced Geographic Information

    Directory of Open Access Journals (Sweden)

    Linda See

    2016-04-01

    Full Text Available Citizens are increasingly becoming an important source of geographic information, sometimes entering domains that had until recently been the exclusive realm of authoritative agencies. This activity has a very diverse character as it can, amongst other things, be active or passive, involve spatial or aspatial data and the data provided can be variable in terms of key attributes such as format, description and quality. Unsurprisingly, therefore, there are a variety of terms used to describe data arising from citizens. In this article, the expressions used to describe citizen sensing of geographic information are reviewed and their use over time explored, prior to categorizing them and highlighting key issues in the current state of the subject. The latter involved a review of ~100 Internet sites with particular focus on their thematic topic, the nature of the data and issues such as incentives for contributors. This review suggests that most sites involve active rather than passive contribution, with citizens typically motivated by the desire to aid a worthy cause, often receiving little training. As such, this article provides a snapshot of the role of citizens in crowdsourcing geographic information and a guide to the current status of this rapidly emerging and evolving subject.

  12. Guidelines for Surveying Bankfull Channel Geometry and Developing Regional Hydraulic-Geometry Relations for Streams of New York State

    Science.gov (United States)

    Powell, Rocky O.; Miller, Sarah J.; Westergard, Britt E.; Mulvihill, Christiane I.; Baldigo, Barry P.; Gallagher, Anne S.; Starr, Richard R.

    2004-01-01

    Many disturbed streams within New York State are being restored in an effort to provide bank and bed stability and thereby decrease sedimentation and erosion. Efforts to identify and provide accurate indicators for stable-channel characteristics for ungaged streams have been hampered by the lack of regional equations or relations that relate drainage area to bankfull discharge and to channel depth, width, and cross-sectional area (bankfull hydraulic-geometry relations). Regional equations are needed to confirm bankfull hydraulic-geometry, assess stream stability, evaluate restoration needs, and verify restoration design for ungaged streams that lack stage-to-discharge ratings or historic peak-flow records. This report presents guidelines for surveying bankfull channel geometry at USGS stream gages and developing regional hydraulic-geometry relations (equations) for wadeable streams in New York. It summarizes methods to (1) compile and assess existing hydrologic, geometric, photographic, and topographic data, (2) conduct stream-reconnaissance inspections, (3) identify channel-bankfull characteristics, (4) conduct longitudinal and cross-section surveys, (5) measure stream discharge, (6) develop and refine bankfull hydraulic-geometry equations, and (7) analyze and assure data completeness and quality. The techniques primarily address wadeable streams with either active or discontinued surface-water and crest-stage gages. The relations can be applied to ungaged or actively gaged streams that are wadeable, and may be extended to non-wadeable streams (with some limitations) if they have drainage areas comparable to those used to develop the relations.

  13. Steady state reach-scale theory for radioactive tracer concentration in a simple channel/floodplain system

    Science.gov (United States)

    Lauer, J. Wesley; Willenbring, Jane

    2010-11-01

    A steady state analytical model is presented for reach-scale variation in the concentration of a decaying radioactive tracer associated with sediment particles that regularly pass through an off-channel floodplain. The floodplain is represented as a series of well-mixed sediment reservoirs that continually exchange sediment with the channel. The model allows for tributary input and valley-wide aggradation or degradation. Tracer concentration depends on the upstream boundary concentration, the tracer and sediment load, floodplain geometry, and the rates of in-floodplain tracer production and/or decay. The theory predicts relatively modest down-channel change in the concentration of long-lived isotopes but implies that significant change may occur for (1) tracers with a short-enough half-life (such as 14C) or (2) floodplains with sediment residence times that are large enough for cosmogenic production or meteoric fallout to increase tracer concentration in the down-valley direction. The profiles are shown to be strongly dependent on the grain size distributions of both the sediment load and the floodplain. The results imply that down-channel 14C profiles have the potential to constrain Holocene bed material loads in systems with sufficient storage. The theory concisely describes the general importance of a floodplain for modifying in situ produced cosmogenic tracer concentration and can also characterize floodplain importance for fallout radioisotopes (i.e., 10Be, 210Pb, or 7Be) or organic 14C.

  14. State Traffic Safety Information - 2010-2015 FARS Accident File data

    Data.gov (United States)

    Department of Transportation — The State Traffic Safety Information (STSI) portal is part of the larger Fatality Analysis Reporting System (FARS) Encyclopedia. STSI provides state-by-state traffic...

  15. Quantum channels with a finite memory

    Science.gov (United States)

    Bowen, Garry; Mancini, Stefano

    2004-01-01

    In this paper we study quantum communication channels with correlated noise effects, i.e., quantum channels with memory. We derive a model for correlated noise channels that includes a channel memory state. We examine the case where the memory is finite, and derive bounds on the classical and quantum capacities. For the entanglement-assisted and unassisted classical capacities it is shown that these bounds are attainable for certain classes of channel. Also, we show that the structure of any finite-memory state is unimportant in the asymptotic limit, and specifically, for a perfect finite-memory channel where no information is lost to the environment, achieving the upper bound implies that the channel is asymptotically noiseless.

  16. Regional flexibility in the S4-S5 linker regulates hERG channel closed-state stabilization.

    Science.gov (United States)

    Hull, Christina M; Sokolov, Stanislav; Van Slyke, Aaron C; Claydon, Tom W

    2014-10-01

    hERG K(+) channel function is vital for normal cardiac rhythm, yet the mechanisms underlying the unique biophysical characteristics of the channel, such as slow activation and deactivation gating, are incompletely understood. The S4-S5 linker is thought to transduce voltage sensor movement to opening of the pore gate, but may also integrate signals from cytoplasmic domains. Previously, we showed that substitutions of G546 within the S4-S5 linker destabilize the closed state of the channel. Here, we present results of a glycine-scan in the background of 546L. We demonstrate site-specific restoration of WT-like activation which suggests that flexibility in the N-terminal portion of the S4-S5 linker is critical for the voltage dependence of hERG channel activation. In addition, we show that the voltage dependence of deactivation, which was recently shown to be left-shifted from that of activation due to voltage sensor mode-shift, is also modulated by the S4-S5 linker. The G546L mutation greatly attenuated the coupling of voltage sensor mode-shift to the pore gate without altering the mode-shift itself. Indeed, all of the S4-S5 linker mutations tested similarly reduced coupling of the mode-shift to the pore gate. These data demonstrate a key role for S4-S5 linker in the unique activation and deactivation gating of hERG channels. Furthermore, uncoupling of the mode-shift to the pore by S4-S5 linker mutations parallels the effects of mutations in the N-terminus suggestive of functional interactions between the two regions.

  17. Dual state-parameter optimal estimation of one-dimensional open channel model using ensemble Kalman filter

    Institute of Scientific and Technical Information of China (English)

    LAI Rui-xun; FANG Hong-wei; HE Guo-jian; YU Xin; YANG Ming; WANG Ming

    2013-01-01

    In this paper,both state variables and parameters of one-dimensional open channel model are estimated using a framework of the Ensemble Kalman Filter (EnKF).Compared with observation,the predicted accuracy of water level and discharge are improved while the parameters of the model are identified simultaneously.With the principles of the EnKF,a state-space description of the Saint-Venant equation is constructed by perturbing the measurements with Gaussian error distribution.At the same time,the roughness,one of the key parameters in one-dimensional open channel,is also considered as a state variable to identify its value dynamically.The updated state variables and the parameters are then used as the initial values of the next time step to continue the assimilation process.The usefulness and the capability of the dual EnKF are demonstrated in the lower Yellow River during the water-sediment regulation in 2009.In the optimization process,the errors between the prediction and the observation are analyzed,and the rationale of inverse roughness is discussed.It is believed that (1) the flexible approach of the dual EnKF can improve the accuracy of predicting water level and discharge,(2) it provides a probabilistic way to identify the model error which is feasible to implement but hard to handle in other filter systems,and (3) it is practicable for river engineering and management.

  18. Robust quantum state transfer via topologically protected edge channels in dipolar arrays

    Science.gov (United States)

    Dlaska, C.; Vermersch, B.; Zoller, P.

    2017-03-01

    We show how to realise quantum state transfer between distant qubits using the chiral edge states of a two-dimensional topological spin system. Our implementation based on Rydberg atoms allows to realise the quantum state transfer protocol in state-of-the-art experimental setups. In particular, we show how to adapt the standard state transfer protocol to make it robust against dispersive and disorder effects.

  19. An influence of spontaneous spike rates on information transmission in a spherical bushy neuron model with stochastic ion channels.

    Science.gov (United States)

    Arata, Hiroki; Mino, Hiroyuki

    2012-01-01

    This article presents an effect of spontaneous spike firing rates on information transmission of the spike trains in a spherical bushy neuron model of antero-ventral cochlear nuclei. In computer simulations, the synaptic current stimuli ascending from auditory nerve fibers (ANFs) were modeled by a filtered inhomogeneous Poisson process modulated with sinusoidal functions, while the stochastic sodium and stochastic high- and low-threshold potassium channels were incorporated into a single compartment model of the soma in spherical bushy neurons. The information rates were estimated from the entropies of the inter-spike intervals of the spike trains to quantitatively evaluate information transmission in the spherical busy neuron model. The results show that the information rates increased, reached a maximum, and then decreased as the rate of spontaneous spikes from the ANFs increased, implying a resonance phenomenon dependent on the rate of spontaneous spikes from ANFs. In conclusion, this phenomenon similar to the stochastic resonance would be observed due to that spontaneous random spike firings coming from auditory nerves may act as an origin of fluctuation or noise, and these findings may play a key role in the design of better auditory prostheses.

  20. Majorana bound states in two-channel time-reversal-symmetric nanowire systems

    DEFF Research Database (Denmark)

    Gaidamauskas, Erikas; Paaske, Jens; Flensberg, Karsten

    2014-01-01

    must be negative, 2) inversion symmetry must be broken, and 3) the two channels must have different spin-orbit couplings. For the case of collinear spin-orbit directions, we find a general expression for the topological invariant by block diagonalization into two blocks with chiral symmetry only....... By projection to the low-energy sector we solve for the zero modes explicitly and study the details of the gap closing, which in the general case happens at finite momenta....

  1. Channel Estimation and Information Symbol Detection for DS-UWB Communication Systems

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2014-01-01

    estimation, the one-step predictor of information symbol is used and the estimation error is also considered as a multiplicative noise. The solutions to the above two problems are obtained by solving a couple of Riccati equations together with two Lyapunov equations.

  2. Using unsteady-state water level data to estimate channel roughness and discharge hydrograph

    Science.gov (United States)

    Aricò, Costanza; Nasello, Carmelo; Tucciarelli, Tullio

    2009-08-01

    A novel methodology for simultaneous discharge and channel roughness estimation is developed and applied to data sets available at three experimental sites. The methodology is based on the synchronous measurement of water level data in two river sections far some kilometers from each other, as well as on the use of a diffusive flow routing solver and does not require any direct velocity measurement. The methodology is first analyzed for the simplest case of a channel with a large slope, where the kinematic assumption holds. A sensitivity and a model error analysis are carried out in this hypothesis in order to show the stability of the results with respect to the error in the input parameters in the case of homogeneous roughness and to analyze the effect of unknown roughness heterogeneity on the estimated discharges. The methodology is then extended to the more general case of channels with mild slope and validated using field data previously collected in three Italian rivers: the Arno (in Tuscany), the Tiber (in Latium) and the Vallo di Diana, a small tributary of the Tanagro river (in Southern Italy). The performance of the proposed algorithm has been investigated according to three performance criteria estimating the quality of the match between the measured and the computed stage and discharge hydrographs. Results of the field tests can be considered good, despite the uncertainties of the field data and of the measured values.

  3. Quadrature Uncertainty and Information Entropy of Quantum Elliptical Vortex States

    OpenAIRE

    Banerji, Anindya; Panigrahi, Prasanta. K.; Singh, Ravindra Pratap; Chowdhury, Saurav; Bandyopadhyay, Abir

    2012-01-01

    We study the quadrature uncertainty of the quantum elliptical vortex state using the associated Wigner function. Deviations from the minimum uncertainty states were observed due to the absence of the Gaussian nature. In our study of the entropy, we noticed that with increasing vorticity, entropy increases for both the modes. We further observed that, there exists an optimum value of ellipticity which gives rise to maximum entanglement of the two modes of the quantum elliptical vortex states. ...

  4. Quantum state transfer via temporal kicking of information

    CERN Document Server

    Di Franco, C; Kim, M S

    2009-01-01

    We propose a strategy for perfect state transfer in spin chains based on the use of an unmodulated coupling Hamiltonian whose coefficients are explicitly time dependent. We show that, if specific and non-demanding conditions are satisfied by the temporal behavior of the coupling strengths, our model allows perfect state transfer. The paradigma put forward by our proposal holds the promises to set an alternative standard to the use of clever encoding and coupling-strength engineering for perfect state transfer.

  5. Benchmarking the State of Yap's Education Management Information System. REL 2016-117

    Science.gov (United States)

    Cicchinelli, Louis F.; Kendall, John S.; Dandapani, Nitara

    2016-01-01

    A quality data management system, such as an education management information system (EMIS), a state longitudinal data system, or a data warehouse, is key to ensuring that education policy, planning, and strategy decisions are grounded in accurate information. The chief state school officers of the Federated States of Micronesia have recognized…

  6. 76 FR 19023 - Commercial Driver's License Information System State Procedures Manual, Release 5.2.0

    Science.gov (United States)

    2011-04-06

    ... Information System State Procedures Manual, Release 5.2.0 AGENCY: Federal Motor Carrier Safety Administration... Driver's License Information System (CDLIS) State Procedures Manual (the Manual). All State driver licensing agencies would use this updated version of the Manual to develop the process required...

  7. 76 FR 68328 - Commercial Driver's License Information System State Procedures Manual, Release 5.2.0

    Science.gov (United States)

    2011-11-04

    ... Information System State Procedures Manual, Release 5.2.0 AGENCY: Federal Motor Carrier Safety Administration... Administrators, Inc.'s (AAMVA) Commercial Driver's License Information System (CDLIS) State Procedures Manual (the Manual) (Release 5.2.0). This final rule requires all State driver licensing agencies (SDLAs)...

  8. Joint random beam and spectrum selection for spectrum sharing systems with partial channel state information

    KAUST Repository

    Abdallah, Mohamed M.

    2013-11-01

    In this work, we develop joint interference-aware random beam and spectrum selection scheme that provide enhanced performance for the secondary network under the condition that the interference observed at the primary receiver is below a predetermined acceptable value. We consider a secondary link composed of a transmitter equipped with multiple antennas and a single-antenna receiver sharing the same spectrum with a set of primary links composed of a single-antenna transmitter and a single-antenna receiver. The proposed schemes jointly select a beam, among a set of power-optimized random beams, as well as the primary spectrum that maximizes the signal-to-interference-plus-noise ratio (SINR) of the secondary link while satisfying the primary interference constraint. In particular, we consider the case where the interference level is described by a q-bit description of its magnitude, whereby we propose a technique to find the optimal quantizer thresholds in a mean square error (MSE) sense. © 2013 IEEE.

  9. Protocol channels as a new design alternative of covert channels

    CERN Document Server

    Wendzel, Steffen

    2008-01-01

    Covert channel techniques are used by attackers to transfer hidden data. There are two main categories of covert channels: timing channels and storage channels. This paper introduces a third category called protocol channels. A protocol channel switches one of at least two protocols to send a bit combination to a destination while sent packets include no hidden information themselves.

  10. Asymptotically Optimal Downlink Scheduling over Markovian Fading Channels

    CERN Document Server

    Ouyang, Wenzhuo; Shroff, Ness B

    2011-01-01

    We consider the scheduling problem in downlink wireless networks with heterogeneous, Markov-modulated, ON/OFF channels. It is well-known that the performance of scheduling over fading channels heavily depends on the accuracy of the available Channel State Information (CSI), which is costly to acquire. Thus, we consider the CSI acquisition via a practical ARQ-based feedback mechanism whereby channel states are revealed at the end of only scheduled users' transmissions. In the assumed presence of temporally-correlated channel evolutions, the desired scheduler must optimally balance the exploitation-exploration trade-off, whereby it schedules transmissions both to exploit those channels with up-to-date CSI and to explore the current state of those with outdated CSI. In earlier works, Whittle's Index Policy had been suggested as a low-complexity and high-performance solution to this problem. However, analyzing its performance in the typical scenario of statistically heterogeneous channel state processes has remai...

  11. To The Question Of Information Security During Rendering State And Municipal Services Through The Global Information And Telecommunication Network Internet

    Directory of Open Access Journals (Sweden)

    Alexander A. Galushkin

    2015-01-01

    Full Text Available In the present article author analyzes some aspects of providing the state and municipal services by means of the global information and telecommunication network Internet. Author proves the need of ensuring information security and counteraction of cyberespionage, gives own offers.

  12. Informal economy as an expression of the state failure

    OpenAIRE

    Agata Kubiczek

    2010-01-01

    The article deals with the phenomenon of second economy, underground or subterranean economy, unofficial economy, unrecorded economy, informal economy, cash economy etc., which has been assessed here as a function of a given mix of economic policies.

  13. The Future of Information Operations in the United States Army

    Science.gov (United States)

    2007-01-01

    as Marketing Marketing tools and concepts could generate support for coalition military operations just as an advertiser promoting a commercial...military, the advanced application of marketing tools to leverage humanitarian assistance and public affairs within an Information Operations plan

  14. Derived Weather State Information via ADS-B Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Innovation Laboratory, Inc, proposes to use Automatic Dependent Surveillance – Broadcast (ADS-B) information as the basis of atmospheric wave and turbulence...

  15. Inverse Determinant Sums and Connections Between Fading Channel Information Theory and Algebra

    CERN Document Server

    Vehkalahti, Roope

    2011-01-01

    Since the invention of space-time coding numerous algebraic methods have been applied to code design. In particular algebraic number theory and central simple algebras have been at the forefront of the research. In the first part of the paper we will push this direction further and show how the error probability of algebraic codes is tied to some central aspects of algebraic number theory and central simple algebras. In particular we prove how the error probability of several algebraic codes is tied to the corresponding zeta functions and unit groups. In the second part of this paper we turn to study what information theory can say about algebra. We will first derive some corollaries from the diversity-multiplexing gain tradeoff (DMT) Zheng and Tse and later show how these results can be used to analyze the unit group of orders of certain division algebras.

  16. State of the Art Review: Information Processing in Microtubules

    Science.gov (United States)

    2009-10-06

    molecules that show multiple electron reversible oxidation-reductions in cyclic voltametry so that every electron acceptance or donation could lead...corresponding to each state; how such a state is derived in a cyclic way? In other words we would like to use the system as analogue to digital...converter where for any random voltage array input, we always get output varying 0 to 7 for 8 level logic system. The cyclic operations may not be

  17. 75 FR 45207 - Proposed Information Collection (Regulation on Reduction of Nursing Shortages in State Homes...

    Science.gov (United States)

    2010-08-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Regulation on Reduction of Nursing Shortages in State Homes...: Regulation on Reduction of Nursing Shortages in State Homes; Application for Assistance for Hiring...

  18. 78 FR 55778 - Proposed Information Collection (Regulation on Reduction of Nursing Shortages in State Homes...

    Science.gov (United States)

    2013-09-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Regulation on Reduction of Nursing Shortages in State Homes...: Regulation on Reduction of Nursing Shortages in State Homes; Application for Assistance for Hiring...

  19. Summary of informal workshop on state of ion beam facilities for atomic physics research

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K.W.; Cocke, C.L.; Datz, S.; Kostroun, V.

    1984-11-13

    The present state of ion beam facilities for atomic physics research in the United States is assessed by means of a questionnaire and informal workshop. Recommendations for future facilities are given. 3 refs.

  20. Chaotic sedimentation of particle pairs in a vertical channel at low Reynolds number: Multiple states and routes to chaos

    Science.gov (United States)

    Verjus, Romuald; Guillou, Sylvain; Ezersky, Alexander; Angilella, Jean-Régis

    2016-12-01

    The sedimentation of a pair of rigid circular particles in a two-dimensional vertical channel containing a Newtonian fluid is investigated numerically, for terminal particle Reynolds numbers (ReT) ranging from 1 to 10, and for a confinement ratio equal to 4. While it is widely admitted that sufficiently inertial pairs should sediment by performing a regular DKT oscillation (Drafting-Kissing-Tumbling), the present analysis shows in contrast that a chaotic regime can also exist for such particles, leading to a much slower sedimentation velocity. It consists of a nearly horizontal pair, corresponding to a maximum effective blockage ratio, and performing a quasiperiodic transition to chaos while increasing the particle weight. For less inertial regimes, the classical oblique doublet structure and its complex behavior (multiple stable states and hysteresis, period-doubling cascade and chaotic attractor) are recovered, in agreement with previous work [Aidun, C. K. and Ding, E.-J., "Dynamics of particle sedimentation in a vertical channel: Period-doubling bifurcation and chaotic state," Phys. Fluids 15, 1612 (2003)]. As a consequence of these various behaviors, the link between the terminal Reynolds number and the non-dimensional driving force is complex: it contains several branches displaying hysteresis as well as various bifurcations. For the range of Reynolds number considered here, a global bifurcation diagram is given.

  1. Power-Controlled Feedback and Training for Two-way MIMO Channels

    OpenAIRE

    Aggarwal, Vaneet; Sabharwal, Ashutosh

    2009-01-01

    Most communication systems use some form of feedback, often related to channel state information. The common models used in analyses either assume perfect channel state information at the receiver and/or noiseless state feedback links. However, in practical systems, neither is the channel estimate known perfectly at the receiver and nor is the feedback link perfect. In this paper, we study the achievable diversity multiplexing tradeoff using i.i.d. Gaussian codebooks, considering the errors i...

  2. Progress in immunization information systems - United States, 2008.

    Science.gov (United States)

    2010-02-12

    Immunization information systems (IISs) are confidential, computerized information systems that collect and consolidate vaccination data from multiple health-care providers, generate reminder and recall notifications, and assess vaccination coverage within a defined geographic area. A CDC program goal for 2010 is to achieve >or=95% participation in an IIS (defined as having two or more recorded vaccinations) among children aged Information Systems Annual Report (IISAR). All 56 grantees were asked to complete the IISAR; 52 did so for 2008. This report highlights results from the 2008 IISAR, which indicated that 75% of all U.S. children aged or=90% of IIS records (both measures are similar to 2006 results). Increased provider use of electronic health record systems can benefit IISs and their users by producing immunization records that are more timely and complete.

  3. Strategizing for Public Policy: The Information Literacy State Proclamation Project

    Science.gov (United States)

    Weiner, Sharon A.; Jackman, Lana W.; Prause, Emily

    2013-01-01

    This article describes a project designed to raise the awareness of policymakers about the importance of information literacy to achieve societal goals. Issues benefit from the governmental support, prioritization, mandates, and funding that can result when there is policy behind them. Studies indicate that many people lack the ability to draw on…

  4. Elections, Private Information, and State-Dependent Candidate Quality

    DEFF Research Database (Denmark)

    Jensen, Thomas

    In this paper we contribute to the study of how democracy works when politicians are better informed than the electorate about conditions relevant for policy choice. We do so by setting up and analyzing a game theoretic model of electoral competition. An important feature of the model is that can...

  5. Information Sharing In Shipbuilding based on the Product State Model

    DEFF Research Database (Denmark)

    Larsen, Michael Holm

    1999-01-01

    The paper provides a review of product modelling technologies and the overall architecture for the Product State Model (PSM) environment as a basis for how dynamically updated product data can improve control of production activities. Especially, the paper focuses on the circumstances prevailing...

  6. Discrete-state representation of ion permeation coupled to fast gating in a model of CLC-chloride channels: analytic estimation of the state-to-state rate constants.

    Science.gov (United States)

    Coalson, Rob D; Cheng, Mary Hongying

    2011-09-01

    Analytical estimation of state-to-state rate constants is carried out for a recently developed discrete state model of chloride ion motion in a CLC chloride channel (Coalson and Cheng, J. Phys. Chem. B 2010, 114, 1424). In the original presentation of this model, the same rate constants were evaluated via three-dimensional Brownian dynamics simulations. The underlying dynamical theory is an appropriate single- or multiparticle three-dimensional Smoluchowski equation. Taking advantage of approximate geometric symmetries (based on the details of the model channel geometry), well-known formulas for state-to-state transition rates are appealed to herein and adapted as necessary to the problem at hand. Rates of ionic influx from a bulk electrolyte reservoir to the nearest binding site within the channel pore are particularly challenging to compute analytically because they reflect multi-ion interactions (as opposed to single-ion dynamics). A simple empirical correction factor is added to the single-ion rate constant formula in this case to account for the saturation of influx rate constants with increasing bulk Cl(-) concentration. Overall, the agreement between all analytically estimated rate constants is within a factor of 2 of those computed via three-dimensional Brownian dynamics simulations, and often better than this. Current-concentration curves obtained using rate constants derived from these two different computational approaches agree to within 25%.

  7. State-dependent FRET reports calcium- and voltage-dependent gating-ring motions in BK channels

    OpenAIRE

    Miranda, Pablo; Contreras, Jorge E.; Plested, Andrew J. R.; Sigworth, Fred J.; Holmgren, Miguel; Giraldez, Teresa

    2013-01-01

    Large-conductance voltage- and calcium-dependent potassium channels (BK, “Big K+”) are important controllers of cell excitability. In the BK channel, a large C-terminal intracellular region containing a “gating-ring” structure has been proposed to transduce Ca2+ binding into channel opening. Using patch-clamp fluorometry, we have investigated the calcium and voltage dependence of conformational changes of the gating-ring region of BK channels, while simultaneously monitoring channel conductan...

  8. State Education Agencies, Information Systems, and the Expansion of State Power in the Era of Test-Based Accountability

    Science.gov (United States)

    Anagnostopoulos, Dorothea; Rutledge, Stacey; Bali, Valentina

    2013-01-01

    This article examines how SEAs in three states designed, installed, and operated statewide, longitudinal student information systems (SLSIS). SLSIS track individual students' progress in K-12 schools, college, and beyond and link it to individual schools and teachers. They are key components of the information infrastructure of test-based…

  9. Quantum Markov Channels for Qubits

    CERN Document Server

    Daffer, S; McIver, J K; Daffer, Sonja; Wodkiewicz, Krzysztof; Iver, John K. Mc

    2003-01-01

    We examine stochastic maps in the context of quantum optics. Making use of the master equation, the damping basis, and the Bloch picture we calculate a non-unital, completely positive, trace-preserving map with unequal damping eigenvalues. This results in what we call the squeezed vacuum channel. A geometrical picture of the effect of stochastic noise on the set of pure state qubit density operators is provided. Finally, we study the capacity of the squeezed vacuum channel to transmit quantum information and to distribute EPR states.

  10. Research on information sharing mechanism of agro-product marketing channel%农产品渠道联盟信息共享机制研究

    Institute of Scientific and Technical Information of China (English)

    车愔

    2011-01-01

    农产品渠道联盟信息共享是指相互合作的渠道成员间在信息上的交流与共用.构建农产品渠道联盟信息共享机制可以使渠道成员增进相互交流、保持协调一致、做出有效的市场预测、提高市场反映速度、以更大的竞争优势达到整个联盟利益最大化,最终实现各成员的特定目标和利益.博弈分析显示,在农产品渠道联盟中,供应商与销售商的信息共享能提高参与信息共享的渠道成员的利润.农产品渠道联盟信息共享机制包括信息共享激励机制和信息共享保障机制.%Agro-product marketing channel alliance in-formation sharing refers to information exchange and sharing between mutual cooperation channel members. The con-structing of agro-product marketing channel alliance informa-tion sharing mechanism can improve mutual communication, coordination and make an effective market forecast, enhances the market reflect speed, realize alliance benefit maximiza-tion with more competitive advantages, and finally achieve every member's specific goals and interests. The game anal-ysis shows that information sharing between the suppliers and sellers can improve profits of involved in agro-product marketing channel alliance. The agro-product marketing channel alliance information sharing mechanism includes in-formation sharing encouragement mechanism and information sharing security mechanism.

  11. State-of-the-art automated patch clamp devices: Heat activation, action potentials and high throughput in ion channel screening

    Directory of Open Access Journals (Sweden)

    Sonja eStoelzle

    2011-11-01

    Full Text Available Ion channels are essential in a wide range of cellular functions and their malfunction underlies many disease states making them important targets in drug discovery. Diverse automated patch clamp systems with high-throughput capabilities are available for drug screening, but there are limitations in the application range. For example, solution exchange time, temperature control and the availability of the current clamp mode can be limiting factors. However, further development of existing devices and introduction of new systems widen the range of possible experiments and increase throughput. Here we introduce new features and platforms that meet the needs of drug discovery researchers and basic researchers alike.The Patchliner is an automated patch clamp system capable of recording up to 8 cells simultaneously with high success rates. Novel features such as temperature control and recordings in the current clamp mode are described here. Standard cell lines and excitable cells such as stem cell-derived cardiomyocytes have been used in the voltage clamp and current clamp modes with the view to finding new drug candidates and safety testing methods in a more physiologically relevant environment. The SyncroPatch 96, is a screening platform capable of recording from 96 cells in parallel and offers a throughput of 5000 data points per day. Full dose response curves can be acquired from individual cells reducing the cost per data point. The system is an ideal tool for secondary screening efforts and for safety testing on ligand- and voltage-gated ion channels.The Patchliner and SyncroPatch 96 are ideal platforms for drug discovery, ion channel research and safety testing, combining long awaited features such as parallel action potential recordings and temperature control with extensively increased throughput.

  12. The evolving state of online search for consumer health information.

    Science.gov (United States)

    Hunscher, Dale A

    2008-11-06

    Online search for consumer health information is a public health concern. General-purpose search engines have historically returned health-related query results of dubious relevance and quality. Meanwhile, consumers have become increasingly reliant on and trusting of these engines. General-purpose search engines have attempted to make their interfaces more consumer-friendly with respect to consumer health queries and their results more relevant and trustworthy. We illustrate the characteristics of the evolving health search landscape using network visualization.

  13. Progress in immunization information systems--United States, 2011.

    Science.gov (United States)

    2013-01-25

    Immunization information systems (IIS) are confidential, computerized, population-based systems that collect and consolidate vaccination data from vaccination providers and provide important tools for designing and sustaining effective immunization strategies. A Healthy People 2020 objective (IID-18) is to increase to 95% the proportion of children aged <6 years whose immunization records are in fully operational, population-based IIS. The National Vaccine Advisory Committee (NVAC) has published goals for IIS, including required and optional core data elements for which IIS should collect information. Two of the required core data elements are vaccine manufacturer and vaccine lot number. To monitor progress toward achieving these and other program goals, CDC annually surveys 56 immunization program grantees using the IIS Annual Report (IISAR). Results from the 2011 IISAR (completed by 54 grantees) indicate that 84% (19.2 million) of U.S. children aged <6 years participated in IIS, as defined by having at least two recorded vaccinations, an increase from 82% (18.8 million) in 2010. Grantees reported that an average of 63% of vaccination records for these children contained data in the field for vaccine manufacturer and 60% contained data in the field for lot number. A new project under way to capture vaccine product information, expiration date, and lot number on two-dimensional (2D) barcodes on vaccine vials might increase completeness, accuracy, and availability of these data elements in patient medical records and IIS, which in turn might enhance vaccine safety and support vaccine inventory management.

  14. Progress in immunization information systems - United States, 2012.

    Science.gov (United States)

    2013-12-13

    Immunization information systems (IIS) are confidential, computerized, population-based systems that collect and consolidate vaccination data from vaccination providers that can be used in designing and sustaining effective immunization strategies. To monitor progress toward achieving IIS program goals, CDC annually surveys immunization program grantees using the IIS Annual Report (IISAR). Results from the 2012 IISAR, completed by 54 of 56 grantees, indicate that 86% (19.5 million) of U.S. children aged <6 years, and 25% (57.8 million) of U.S. adults participated in IIS. Eight of 12 minimum functional standards for IIS published by the National Vaccine Advisory Committee (NVAC) have been met by ≥90% of grantees. During 2011-2012, progress was also made in meeting three additional functional standards, including the presence of core data element fields, timeliness of vaccine records, and Health Level 7 (HL7) messaging, and will be monitored in new functional standards for IIS published in 2013. Several new and ongoing initiatives, including interoperability between IIS and electronic health records (i.e., ensuring systems can work together and exchange information), the use of IIS to support vaccine ordering and inventory management, the use of two-dimensional barcodes to record vaccination information, and collaboration with pharmacies, federal agencies, and other adult vaccination providers, will support further progress in meeting functional standards and enhance reporting of adult vaccinations to IIS.

  15. Hydrophobic interactions between the S5 segment and the pore helix stabilizes the closed state of Slo2.1 potassium channels.

    Science.gov (United States)

    Suzuki, Tomoyuki; Hansen, Angela; Sanguinetti, Michael C

    2016-04-01

    Under normal physiological conditions, Slo2.1K(+) channels are in a closed state unless activated by an elevation in [Na(+)]i. Fenamates such as niflumic acid also activate Slo2.1. Previous studies suggest that activation of Slo2.1 channels is mediated by a conformational change in the selectivity filter, and not a widening of the aperture formed by the S6 segment bundle crossing as occurs in voltage-gated K(+) channels. It is unclear how binding of Na(+) or fenamates is allosterically linked to opening of the presumed selectivity filter activation gate in Slo2.1. Here we examined the role of the S5 transmembrane segment in the activation of Slo2.1. Channels were heterologously expressed in Xenopus laevis oocytes and whole cell currents measured with the voltage-clamp technique. Ala substitution of five residues located on a single face of the S5 α-helical segment induced constitutive channel activity. Leu-209, predicted to face towards Phe-240 in the pore helix was investigated by further mutagenesis. Mutation of Leu-209 to Glu or Gln induced maximal channel activation as did the combined mutation to Ala of all three hydrophobic S5 residues predicted to be adjacent to Phe-240. Together these results suggest that hydrophobic interactions between residues in S5 and the C-terminal end of the pore helix stabilize Slo2.1 channels in a closed state.

  16. Motivating Factors of Florida Community and State College Information Technology Faculty

    Science.gov (United States)

    Payne, Wendy Louise

    2013-01-01

    In this study the core job characteristics that contribute to the internal motivational factors and job satisfaction of information technology faculty members working at a community or state college in Florida were investigated. Fifty-four information technology faculty members working at a community or state college in Florida completed the Job…

  17. Information and Resources on Developing State Policy on Kindergarten Entry Assessment (KEA). CEELO FastFacts

    Science.gov (United States)

    Connors-Tadros, L.

    2014-01-01

    The Center on Enhancing Early Learning Outcomes (CEELO) was asked to provide information on how other states are approaching the development and implementation of Kindergarten Entry Assessment (KEA) as part of a comprehensive assessment system. Specifically, the request asked for information about KEA measures used by other states, the processes…

  18. Von Neumann entropy, mutual information and total correlations of Gaussian states

    CERN Document Server

    Serafini, A; De Siena, S; Serafini, Alessio; Illuminati, Fabrizio; Siena, Silvio De

    2004-01-01

    We determine the Von Neumann entropy and the mutual information of an arbitrary bipartite Gaussian state. A comparison between mutual information and entanglement of formation for symmetric states is considered, remarking the crucial role of the symplectic eigenvalues in qualifying and quantifying correlations.

  19. Method of sharing mobile unit state information between base station routers

    NARCIS (Netherlands)

    Bosch, Peter; Mullender, Sape J.; Polakos, Paul Anthony; Rajkumar, Ajay; Sundaram, Ganapathy S.

    2010-01-01

    The present invention provides a method of operating a first base station router. The method may include transmitting state information associated with at least one inactive mobile unit to at least one second base station router. The state information is usable to initiate an active session with the

  20. Method of sharing mobile unit state information between base station routers

    NARCIS (Netherlands)

    Bosch, Peter; Mullender, Sape J.; Polakos, Paul Anthony; Rajkumar, Ajay; Sundaram, Ganapathy S.

    2008-01-01

    The present invention provides a method of operating a first base station router. The method may include transmitting state information associated with at least one inactive mobile unit to at least one second base station router. The state information is usable to initiate an active session with the

  1. 78 FR 12349 - Proposed Information Collection; Land and Water Conservation Fund State Assistance Program

    Science.gov (United States)

    2013-02-22

    ... National Park Service Proposed Information Collection; Land and Water Conservation Fund State Assistance... INFORMATION: I. Abstract The Land and Water Conservation Fund Act of 1965 (LWCF Act) (16 U.S.C. 460l-4 et seq... discussed in detail in the Land and Water Conservation Fund State Assistance Program Federal...

  2. Review: The state-of-art of sparse channel models and their applicability to performance assessment of radioactive waste repositories in fractured crystalline formations

    Science.gov (United States)

    Figueiredo, Bruno; Tsang, Chin-Fu; Niemi, Auli; Lindgren, Georg

    2016-11-01

    Laboratory and field experiments done on fractured rock show that flow and solute transport often occur along flow channels. `Sparse channels' refers to the case where these channels are characterised by flow in long flow paths separated from each other by large spacings relative to the size of flow domain. A literature study is presented that brings together information useful to assess whether a sparse-channel network concept is an appropriate representation of the flow system in tight fractured rock of low transmissivity, such as that around a nuclear waste repository in deep crystalline rocks. A number of observations are made in this review. First, conventional fracture network models may lead to inaccurate results for flow and solute transport in tight fractured rocks. Secondly, a flow dimension of 1, as determined by the analysis of pressure data in well testing, may be indicative of channelised flow, but such interpretation is not unique or definitive. Thirdly, in sparse channels, the percolation may be more influenced by the fracture shape than the fracture size and orientation but further studies are needed. Fourthly, the migration of radionuclides from a waste canister in a repository to the biosphere may be strongly influenced by the type of model used (e.g. discrete fracture network, channel model). Fifthly, the determination of appropriateness of representing an in situ flow system by a sparse-channel network model needs parameters usually neglected in site characterisation, such as the density of channels or fracture intersections.

  3. Review: The state-of-art of sparse channel models and their applicability to performance assessment of radioactive waste repositories in fractured crystalline formations

    Science.gov (United States)

    Figueiredo, Bruno; Tsang, Chin-Fu; Niemi, Auli; Lindgren, Georg

    2016-05-01

    Laboratory and field experiments done on fractured rock show that flow and solute transport often occur along flow channels. `Sparse channels' refers to the case where these channels are characterised by flow in long flow paths separated from each other by large spacings relative to the size of flow domain. A literature study is presented that brings together information useful to assess whether a sparse-channel network concept is an appropriate representation of the flow system in tight fractured rock of low transmissivity, such as that around a nuclear waste repository in deep crystalline rocks. A number of observations are made in this review. First, conventional fracture network models may lead to inaccurate results for flow and solute transport in tight fractured rocks. Secondly, a flow dimension of 1, as determined by the analysis of pressure data in well testing, may be indicative of channelised flow, but such interpretation is not unique or definitive. Thirdly, in sparse channels, the percolation may be more influenced by the fracture shape than the fracture size and orientation but further studies are needed. Fourthly, the migration of radionuclides from a waste canister in a repository to the biosphere may be strongly influenced by the type of model used (e.g. discrete fracture network, channel model). Fifthly, the determination of appropriateness of representing an in situ flow system by a sparse-channel network model needs parameters usually neglected in site characterisation, such as the density of channels or fracture intersections.

  4. Evaluation of Origin Ensemble algorithm for image reconstruction for pixelated solid-state detectors with large number of channels

    Science.gov (United States)

    Kolstein, M.; De Lorenzo, G.; Mikhaylova, E.; Chmeissani, M.; Ariño, G.; Calderón, Y.; Ozsahin, I.; Uzun, D.

    2013-04-01

    The Voxel Imaging PET (VIP) Pathfinder project intends to show the advantages of using pixelated solid-state technology for nuclear medicine applications. It proposes designs for Positron Emission Tomography (PET), Positron Emission Mammography (PEM) and Compton gamma camera detectors with a large number of signal channels (of the order of 106). For PET scanners, conventional algorithms like Filtered Back-Projection (FBP) and Ordered Subset Expectation Maximization (OSEM) are straightforward to use and give good results. However, FBP presents difficulties for detectors with limited angular coverage like PEM and Compton gamma cameras, whereas OSEM has an impractically large time and memory consumption for a Compton gamma camera with a large number of channels. In this article, the Origin Ensemble (OE) algorithm is evaluated as an alternative algorithm for image reconstruction. Monte Carlo simulations of the PET design are used to compare the performance of OE, FBP and OSEM in terms of the bias, variance and average mean squared error (MSE) image quality metrics. For the PEM and Compton camera designs, results obtained with OE are presented.

  5. Minimal classical communication and measurement complexity for quantum information splitting of a two-qubit state

    Indian Academy of Sciences (India)

    Prasanta K Panigrahi; Siddharth Karumanchi; Sreraman Muralidharan

    2009-09-01

    We investigate the usefulness of the highly entangled five-partite cluster and Brown states for the quantum information splitting (QIS) of a special kind of two-qubit state using remote state preparation. In our schemes, the information that is to be shared is known to the sender. We show that, QIS can be accomplished with just two classical bits, as opposed to four classical bits, when the information that is to be shared is unknown to the sender. The present algorithm, demonstrated through the cluster and Brown states is deterministic as compared to the previous works in which it was probabilistic.

  6. Entanglement enhanced bit rate over multiple uses of a lossy bosonic channel with memory

    Science.gov (United States)

    Lupo, C.; Mancini, S.

    2010-03-01

    We present a study of the achievable rates for classical information transmission via a lossy bosonic channel with memory, using homodyne detection. A comparison with the memoryless case shows that the presence of memory enhances the bit rate if information is encoded in collective states, i.e., states which are entangled over different uses of the channel.

  7. The State of the Art in Information Handling. Operation PEP/Executive Information Systems.

    Science.gov (United States)

    Summers, J. K.; Sullivan, J. E.

    This document explains recent developments in computer science and information systems of interest to the educational manager. A brief history of computers is included, together with an examination of modern computers' capabilities. Various features of card, tape, and disk information storage systems are presented. The importance of time-sharing…

  8. Resolving the 3D spatial orientation of helix I in the closed state of the colicin E1 channel domain by FRET. Insights into the integration mechanism.

    Science.gov (United States)

    Lugo, Miguel R; Ho, Derek; Merrill, A Rod

    2016-10-15

    Current evidence suggests that the closed-state membrane model for the channel-forming domain of colicin E1 involves eight amphipathic α-helices (helices I-VII and X) that adopt a two-dimensional arrangement on the membrane surface. Two central hydrophobic α-helices in colicin E1 (VIII and IX) adopt a transmembrane location-the umbrella model. Helices I and II have been shown to participate in the channel by forming a transmembrane segment (TM1) in the voltage-induced open channel state. Consequently, it is paramount to determine the relative location and orientation of helix I in the two-dimensional arrangement of the membrane. A new, low-resolution, three-dimensional model of the closed state of the colicin E1 channel was constructed based on FRET measurements between three naturally occurring Trp residues and three sites in helix I, in addition to previously reported FRET distances for the channel domain. Furthermore, a new mechanism for the channel integration process involving the transition of the soluble to membrane-bound form is presented based on a plethora of kinetic data for this process.

  9. Extracting Information about the Initial State from the Black Hole Radiation.

    Science.gov (United States)

    Lochan, Kinjalk; Padmanabhan, T

    2016-02-05

    The crux of the black hole information paradox is related to the fact that the complete information about the initial state of a quantum field in a collapsing spacetime is not available to future asymptotic observers, belying the expectations from a unitary quantum theory. We study the imprints of the initial quantum state contained in a specific class of distortions of the black hole radiation and identify the classes of in states that can be partially or fully reconstructed from the information contained within. Even for the general in state, we can uncover some specific information. These results suggest that a classical collapse scenario ignores this richness of information in the resulting spectrum and a consistent quantum treatment of the entire collapse process might allow us to retrieve much more information from the spectrum of the final radiation.

  10. Infodynamics: Analogical Analysis of States of Matter and Information

    Science.gov (United States)

    2007-01-01

    On the Shannon measure of entropy, Information Sciences 23 (1) (1981) 1–9. [2] G.W. Castellan , Physical Chemistry, Addison-Wesley Publishing Co...Reading, MA, 1964, pp. 11–13. [3] G.W. Castellan , Physical Chemistry, Addison-Wesley Publishing Co., Reading, MA, 1964, pp. 291–296. [4] G.W. Castellan ...Physical Chemistry, Addison-Wesley Publishing Co., Reading MA, 1964, pp. 38–40. [5] G.W. Castellan , Physical Chemistry, Addison-Wesley Publishing Co

  11. Chaotic sedimentation of particle pairs in a vertical channel at low Reynolds number: multiple states and routes to chaos

    CERN Document Server

    Verjus, Romuald; Ezersky, Alexander; Angilella, Jean-Régis

    2016-01-01

    The sedimentation of a pair of rigid circular particles in a two-dimensional vertical channel containing a Newtonian fluid is investigated numerically, for terminal particle Reynolds numbers ranging from 1 to 10, and for a confinement ratio equal to 4. While it is widely admitted that sufficiently inertial pairs should sediment by performing a regular DKT oscillation (Drafting-Kissing-Tumbling), the present analysis shows in contrast that a chaotic regime can also exist for such particles, leading to a much slower sedimentation velocity. It consists of a nearly horizontal pair, corresponding to a maximum effective blockage ratio, and performing a quasiperiodic transition to chaos under increasing the particle weight. For less inertial regimes, the classical oblique doublet structure and its complex behavior (multiple stable states and hysteresis, period-doubling cascade and chaotic attractor) are recovered, in agreement with previous work [Aidun & Ding, Physics of Fluids 15(6), 2003]. As a consequence of ...

  12. Channel dropping via bound states in the continuum in a system of two nonlinear cavities between two linear waveguides.

    Science.gov (United States)

    Bulgakov, Evgeny; Pichugin, Konstantin; Sadreev, Almas

    2013-10-01

    We show that two nonlinear resonant cavities aligned between two parallel waveguides can support self-induced bound states in the continuum (BSCs). These BSCs are symmetrical relative to an inversion of the waveguides and to inversion of the transport axis. Due to this BSCs can drop an incident wave from one waveguide to another with very high efficiency. We show also that the frequency of the efficient channel dropping can be tuned by injecting power. All these results are in good agreement with numerical solutions of the Maxwell equations in a two-dimensional photonic crystal of GaAs rods holding two parallel waveguides and two defects made of a Kerr medium.

  13. Information technology issues in an era of greater state responsibilities: policy concerns for seniors.

    Science.gov (United States)

    Shrewsbury, Carolyn M

    2002-01-01

    Five areas of state information technology policy are of special concern to seniors and senior service providers: obtaining access; closing the digital divide; developing information management systems; creating portals; and maintaining privacy. Increasing their activities in each of these areas, states continue to vary considerably in their responsiveness to meeting the challenge of including older adults, especially those living in rural areas, with the benefits of information technology.

  14. New Mexico state information handbook: formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-12-31

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the State of New Mexico. It contains a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; and the full text of relevant statutes and regulations.

  15. New York state information handbook formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-31

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying our the Formerly Utilized Sites Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the State of New York. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; and the full text of relevant statutes and regulations.

  16. 78 FR 23288 - Proposed Information Collection: State Water Resources Research Institute Program; Annual...

    Science.gov (United States)

    2013-04-18

    ... Geological Survey Proposed Information Collection: State Water Resources Research Institute Program; Annual...: eagreene@usgs.gov . SUPPLEMENTARY INFORMATION: I. Abstract The Water Resources Research Act of 1984, as... extension of an information collection (1028- 0097); request for comments. SUMMARY: To comply with...

  17. 75 FR 27575 - Agency Information Collection Activities: State Water Resources Research Institute Program Annual...

    Science.gov (United States)

    2010-05-17

    ... Geological Survey Agency Information Collection Activities: State Water Resources Research Institute Program... notifying the public that we have submitted to the Office of Management and Budget (OMB) an information... collection of information unless it displays a currently valid OMB control number. DATES: You must...

  18. 78 FR 46597 - Agency Information Collection Activities: State Water Resources Research Institute Program Annual...

    Science.gov (United States)

    2013-08-01

    ....S. Geological Survey Agency Information Collection Activities: State Water Resources Research...: Notice of an extension of currently approved information Collection, 1028-0097. SUMMARY: To comply with... an information collection request (ICR) that we have sent to the Office of Management and Budget...

  19. 78 FR 5793 - Agency Information Collection Activities; Comment Request; Evaluation of State Expanded Learning...

    Science.gov (United States)

    2013-01-28

    ... Agency Information Collection Activities; Comment Request; Evaluation of State Expanded Learning Time... Reduction Act of 1995 (44 U.S.C. chapter 3501 et seq.), ED is proposing a new information collection. DATES... submitted after the comment period will not be accepted. Written requests for information or...

  20. 78 FR 55252 - Proposed Information Collection Request; Comment Request; State Review Framework

    Science.gov (United States)

    2013-09-10

    ... state performance in enforcement and compliance assurance. The Framework's goal is to evaluate state... AGENCY Proposed Information Collection Request; Comment Request; State Review Framework AGENCY... Framework (EPA ICR No. 2185.05, OMB Control No. 2020-0031) to the Office of Management and Budget (OMB)...

  1. A Summary of State Chapter 1 Participation and Achievement Information for 1987-88.

    Science.gov (United States)

    Sinclair, Beth; Gutmann, Babette

    This document summarizes the annual State Performance Reports for programs funded under Chapter 1 of the Education Consolidation and Improvement Act (ECIA), which have been submitted by State Education Agencies (SEAs) for the school years 1979-80 through 1987-88. These reports provide information on Local Education Agency (LEA) and State Agency…

  2. A Summary of State Chapter 1 Participation and Achievement Information for 1986-87.

    Science.gov (United States)

    Steele, Diane; Gutmann, Babette

    This document summarizes the State Performance Reports for programs funded under Chapter 1 of the Education Consolidation and Improvement Act for 1986-87. Reports are submitted annually by State Education Agencies (SEAs) to provide information on Local Education Agency (LEA) and State Agency Neglected or Delinquent (SAND) compensatory education…

  3. Robust Lattice Alignment for K-user MIMO Interference Channels with Imperfect Channel Knowledge

    CERN Document Server

    Huang, Huang; Du, Yinggang; Liu, Sheng

    2011-01-01

    In this paper, we consider a robust lattice alignment design for K-user quasi-static MIMO interference channels with imperfect channel knowledge. With random Gaussian inputs, the conventional interference alignment (IA) method has the feasibility problem when the channel is quasi-static. On the other hand, structured lattices can create structured interference as opposed to the random interference caused by random Gaussian symbols. The structured interference space can be exploited to transmit the desired signals over the gaps. However, the existing alignment methods on the lattice codes for quasi-static channels either require infinite SNR or symmetric interference channel coefficients. Furthermore, perfect channel state information (CSI) is required for these alignment methods, which is difficult to achieve in practice. In this paper, we propose a robust lattice alignment method for quasi-static MIMO interference channels with imperfect CSI at all SNR regimes, and a two-stage decoding algorithm to decode th...

  4. Catalyst-like modulation of transition states for CFTR channel opening and closing: New stimulation strategy exploits nonequilibrium gating

    OpenAIRE

    Csanády, László; Töröcsik, Beáta

    2014-01-01

    Cystic fibrosis transmembrane conductance regulator (CFTR) is the chloride ion channel mutated in cystic fibrosis (CF) patients. It is an ATP-binding cassette protein, and its resulting cyclic nonequilibrium gating mechanism sets it apart from most other ion channels. The most common CF mutation (ΔF508) impairs folding of CFTR but also channel gating, reducing open probability (Po). This gating defect must be addressed to effectively treat CF. Combining single-channel and macroscopic current ...

  5. Mobile radio channels

    CERN Document Server

    Pätzold, Matthias

    2011-01-01

    Providing a comprehensive overview of the modelling, analysis and simulation of mobile radio channels, this book gives a detailed understanding of fundamental issues and examines state-of-the-art techniques in mobile radio channel modelling. It analyses several mobile fading channels, including terrestrial and satellite flat-fading channels, various types of wideband channels and advanced MIMO channels, providing a fundamental understanding of the issues currently being investigated in the field. Important classes of narrowband, wideband, and space-time wireless channels are explored in deta

  6. Optimization of bandwidth of communication channels of corporate networks

    Directory of Open Access Journals (Sweden)

    G. I. Bondarenko

    2014-09-01

    Full Text Available Introduction. This article contains overview of the organization of communication between applications on the corporate network. It is stated that the main digital channel (channel B - 64 kbit/s and the primary digital channel (channel E1 the digital stream - 2048 kbit/s are used as the main channels in corporate networks. Problem areas of the functioning of the corporate network are identified. There are the rent of communication channels, which is growing rapidly with increasing the quality and speed of data transmission, and optimal use of bandwidth of communication channels. Setting of task. Optimal use of transmission channels bandwidth and minimizing the rent cost of channels is possible in two ways - the use of compression techniques of voice and video information and the application of variable structure of channels by using various-speed transmission channels. Differential pulse code modulation, adaptive differential pulse code modulation are the modern methods of speech signals processing. Organization of various-speed channels is performed in the structure of the BCC (for speech signals or PCR (for video. Suggestions for optimizing the structure of the channel signals. Proposed method of various-speed channels formation by using the channel intervals appropriate BCC (octets in the structure of signals E1 as envelopes containing various-speed channels. Channels can be selected for synchronization procedure CRC to simplify recognition of channels in the structure of E1. In this case, the minimal speed in the channel is 4 kbit/s. Conclusions. The proposed structure of envelopes is based on octet channel intervals of standard group signal of the primary group plesiochronous hierarchy E1 when transferring various-speed digital signals maximum allows to use the bandwidth at a fixed structure of channel interval, it makes possible to agree on the structure of the various-speed signals with the existing in communication networks.

  7. Information Technology and Art: Concepts and State of the Practice

    Science.gov (United States)

    Ahmed, Salah Uddin; Camerano, Cristoforo; Fortuna, Luigi; Frasca, Mattia; Jaccheri, Letizia

    The interaction between information technology (IT) and art is an increasing trend. Science, art and technology have been connected since the 60's, when scientists, artists, and inventors started to cooperate and use electronic instruments to create art. In 1960 Marshall McLuhan predicted the idea that the era of "machine-age" technology was next to close, and the electronic media were creating a new way to perform art [1]. The literature is full with examples of artists applying mathematics, robotic technology, and computing to the creation of art. The work in [2] is a good introduction to the merge of IT and art and introduces genetic art, algorithmic art, applications of complex systems and artificial intelligence. The intersection is drawing attention of people from diverse background and it is growing in size and scope. For these reasons, it is beneficiary for people interested in art and technology to know each other's background and interests well. In a multidisciplinary collaboration, the success depends on how well the different actors in the project collaborate and understand each other. See [3] for an introduction about multidisciplinary issues. Meyer and others in [4] explains the collaboration process between artists and technologists.

  8. Atomic determinants of state-dependent block of sodium channels by charged local anesthetics and benzocaine.

    Science.gov (United States)

    Tikhonov, Denis B; Bruhova, Iva; Zhorov, Boris S

    2006-11-13

    Molecular modeling predicts that a local anesthetic (LA) lidocaine binds to the resting and open Na(v)1.5 in different modes, interacting with LA-sensing residues known from experiments. Besides the major pathway via the open activation gate, LAs can reach the inner pore via a "sidewalk" between D3S6, D4S6, and D3P. The ammonium group of a cationic LA binds in the focus of the pore-helices macrodipoles, which also stabilize a Na(+) ion chelated by two benzocaine molecules. The LA's cationic group and a Na(+) ion in the selectivity filter repel each other suggesting that the Na(+) depletion upon slow inactivation would stabilize a LA, while a LA would stabilize slow-inactivated states.

  9. Charge states distribution of 3350 keV He ions channeled in silicon

    CERN Document Server

    Bentini, G G; Bianconi, M; Lotti, R; Lulli, G

    2002-01-01

    When an ion beam is aligned along a major crystalline axis the dominant interaction is with valence electrons. In this condition the charge exchange processes mostly concern the interaction between the incident ion and a quasi-free electron gas and a strong reduction of the charge-changing probabilities is expected. In this work, 3350 keV He sup + and He sup 2 sup + ions were aligned at small tilt angles about the axis of a 4650 A silicon crystalline membrane. The charge state distribution (CSD) of the transmitted ions was detected by an electro-magnetic analyzer having a very small acceptance angle. In these conditions the equilibration of the CSD was not yet reached and this allowed, making use of simple approximations, for the measurement of the valence electron loss cross-section.

  10. 78 FR 48198 - Comment Request for Information Collection for Workforce Information Grants to States, Extension...

    Science.gov (United States)

    2013-08-07

    ... Revisions AGENCY: Employment and Training Administration (ETA), Labor. ACTION: Notice. SUMMARY: The U.S... ). SUPPLEMENTARY INFORMATION: I. Background On July 24, 2011, OMB approved ETA's annual policy guidance and... Reduction Act (PRA) of 1995 [44 U.S.C. 3506(c)(2)(A)]. This program helps ensure that requested data can...

  11. Effectiveness of Information Technology Infrastructure Library Process Implementations by Information Technology Departments within United States Organizations

    Science.gov (United States)

    Persinger, Jon F.

    2010-01-01

    This research study examined whether the overall effectiveness of the Information Technology Infrastructure Library (ITIL) could be predicted by measuring multiple independent variables. The primary variables studied included the number of ITIL process modules adopted and the overall ITIL "maturity level." An online survey was used to…

  12. Drug binding to the inactivated state is necessary but not sufficient for high-affinity binding to human ether-à-go-go-related gene channels.

    Science.gov (United States)

    Perrin, Mark J; Kuchel, Philip W; Campbell, Terence J; Vandenberg, Jamie I

    2008-11-01

    Drug block of the human ether-à-go-go-related gene K(+) channel (hERG) is the most common cause of acquired long QT syndrome, a disorder of cardiac repolarization that may result in ventricular tachycardia and sudden cardiac death. We investigated the open versus inactivated state dependence of drug block by using hERG mutants N588K and N588E, which shift the voltage dependence of inactivation compared with wild-type but in which the mutated residue is remote from the drug-binding pocket in the channel pore. Four high-affinity drugs (cisapride, dofetilide, terfenadine, and astemizole) demonstrated lower affinity for the inactivation-deficient N588K mutant hERG channel compared with N588E and wild-type hERG. Three of four low-affinity drugs (erythromycin, perhexiline, and quinidine) demonstrated no preference for N588E over N588K channels, whereas dl-sotalol was an example of a low-affinity state-dependent blocker. All five state-dependent blockers showed an even lower affinity for S620T mutant hERG (no inactivation) compared with N588K mutant hERG (greatly reduced inactivation). Computer modeling indicates that the reduced affinity for S620T compared with N588K and wild-type channels can be explained by the relative kinetics of drug block and unblock compared with the kinetics of inactivation and recovery from inactivation. We were also able to calculate, for the first time, the relative affinities for the inactivated versus the open state, which for the drugs tested here ranged from 4- to 70-fold. Our results show that preferential binding to the inactivated state is necessary but not sufficient for high-affinity binding to hERG channels.

  13. Near-Nash equilibrium strategies for LQ differential games with inaccurate state information

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available ε -Nash equilibrium or “near equilibrium” for a linear quadratic cost game is considered. Due to inaccurate state information, the standard solution for feedback Nash equilibrium cannot be applied. Instead, an estimation of the players' states is substituted into the optimal control strategies equation obtained for perfect state information. The magnitude of the ε in the ε -Nash equilibrium will depend on the quality of the estimation process. To illustrate this approach, a Luenberger-type observer is used in the numerical example to generate the players' state estimates in a two-player non-zero-sum LQ differential game.

  14. Information Fusing Recognition of Traditional Chinese Medicine (TCM) Pulse State Based on Stochastic Fuzzy Neural Network

    Institute of Scientific and Technical Information of China (English)

    QIN Jian; LIU Hong-jian; DENG Wei; WU Guo-zhen; CHEN Shu-qing; JING Ming-hua

    2005-01-01

    Based on the fuzzy characteristic of the pulse state and syndromes differentiation thinking mode of TCM, an information fusing recognition method of pulse states based on SFNN (Stochastic Fuzzy Neural Network) is presented in this paper. With the learning ability in parameters and structure, SFNN fuses the measurement information of three pulse-state sensors distributed in Cun, Guan,and Chi location of body for the pulse state recognition. The experimental results show that the percentage of correct recognition with new method is higher than that by single-data recognition one, with fewer off-line train numbers.

  15. Fast-onset lidocaine block of rat NaV1.4 channels suggests involvement of a second high-affinity open state.

    Science.gov (United States)

    Gingrich, Kevin J; Wagner, Larry E

    2016-06-01

    Local anesthetics (LAs) block resting, open, and inactivated states of voltage-gated Na(+) channels where inactivated states are thought to bind with highest affinity. However, reports of fast-onset block occurring over milliseconds hint at high-affinity block of open channels. Movement of voltage-sensor domain IV-segment 4 (DIVS4) has been associated with high affinity LA block termed voltage-sensor block (VSB) that also leads to a second open state. These observations point to a second high-affinity open state that may underlie fast-onset block. To test for this state, we analyzed the modulation of Na(+) currents by lidocaine and its quaternary derivative (QX222) from heterologously expressed (Xenopus laevis oocytes) rat skeletal muscle μ1 NaV1.4 (rSkM1) with β1 (WT-β1), and a mutant form (IFM-QQQ mutation in the III-IV interdomain, QQQ) lacking fast inactivation, in combination with Markov kinetic gating models. 100 μM lidocaine induced fast-onset (τonset≈2 ms), long-lived (τrecovery≈120 ms) block of WT-β1 macroscopic currents. Lidocaine blocked single-channel and macroscopic QQQ currents in agreement with our previously described mechanism of dual, open-channel block (DOB mechanism). A DOB kinetic model reproduced lidocaine effects on QQQ currents. The DOB model was extended to include trapping fast-inactivation and activation gates, and a second open state (OS2); the latter arising from DIVS4 translocation that precedes inactivation and exhibits high-affinity, lidocaine binding (apparent Kd=25 μM) that accords with VSB (DOB-S2VSB mechanism). The DOB-S2VSB kinetic model predicted fast-onset block of WT-β1. The findings support the involvement of a second, high-affinity, open state in lidocaine modulation of Na(+) channels.

  16. Three-mode Gaussian states in quantum information with continuous variables

    CERN Document Server

    Adesso, G; Serafini, A; Adesso, Gerardo; Illuminati, Fabrizio; Serafini, Alessio

    2006-01-01

    The structural aspects of tripartite entanglement in three-mode Gaussian states of continuous variable systems have been studied in [Adesso G, Serafini A and Illuminati F 2006 Phys. Rev. A {\\bf 73} 032345]. Here we focus our attention on the usefulness of such states in the context of realistic processing of continuous-variable quantum information. We introduce and discuss in detail several examples of pure and mixed three-mode states that stand out for their informational and/or entanglement properties. We then describe practical schemes to engineer such states with linear optics. In particular, we introduce a simple procedure -- based on passive optical elements -- to produce pure three-mode Gaussian states with {\\em arbitrary} entanglement structure (upon availability of an initial single-mode squeezed state). We analyze in detail the properties of distributed entanglement, showing that the promiscuity of entanglement sharing is a feature peculiar to symmetric Gaussian states that survives even in the pres...

  17. New Mexico state information handbook formerly utilized sites remedial action program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-12-31

    This volume is one of a series produced under contract with the DOE, by Politech Corporation to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Formerly Utilized Sites Remedial Action Program. This Informaion Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the State of New Mexico. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; and the full text of relevant statutes and regulations.

  18. Crowdsourcing, citizen science or volunteered geographic information? The current state of crowdsourced geographic information

    OpenAIRE

    See, Linda; Mooney, Peter; Foody, Giles; Bastin, Lucy; COMBER Alexis; Estima, Jacinto; Fritz, Steffen; Kerle, Norman; Jiang, Bin; Laakso, Mari; Liu, Hai Ying; Milčinski, Grega; Nikšieč, Matej; Painho, Marco; Pődör, Andrea

    2016-01-01

    Citizens are increasingly becoming an important source of geographic information, sometimes entering domains that had until recently been the exclusive realm of authoritative agencies. This activity has a very diverse character as it can, amongst other things, be active or passive, involve spatial or aspatial data and the data provided can be variable in terms of key attributes such as format, description and quality. Unsurprisingly, therefore, there are a variety of terms used to describe da...

  19. Crowdsourcing, Citizen Science or Volunteered Geographic Information? The Current State of Crowdsourced Geographic Information

    OpenAIRE

    L. See; P. Mooney; Foody, G; L. Bastin; Comber, A; Estima, J; Fritz, S; KERLE N.; Jiang, B; Laakso, M; Liu, HY; Milcinski, G.; Nikšieč, M; Painho, M.; Podör, A.

    2016-01-01

    Citizens are increasingly becoming an important source of geographic information, sometimes entering domains that had until recently been the exclusive realm of authoritative agencies. This activity has a very diverse character as it can, amongst other things, be active or passive, involve spatial or aspatial data and the data provided can be variable in terms of key attributes such as format, description and quality. Unsurprisingly, therefore, there are a variety of terms used to describe da...

  20. Size effects on the open probability of two-state ion channel system in cell membranes using microcanonical formalism based on gamma function

    Science.gov (United States)

    Erdem, Riza; Aydiner, Ekrem

    2016-08-01

    Ion channel systems are a class of proteins that reside in the membranes of all biological cells and forms conduction pores that regulate the transport of ions into and out of cells. They can be investigated theoretically in the microcanonical formalism since the number of accessible states can be easily evaluated by using the Stirling approximation to deal with factorials. In this work, we have used gamma function (Γ (n)) to solve the two-state or open-close channel model without any approximation. New values are calculated for the open probability (p0) and the relative error between our numerical results and the approximate one using Stirling formula is presented. This error (p0 app — p0)/p0 is significant for small channel systems.

  1. Quantum Teleportation of Tripartite Arbitrary State via W State

    Institute of Scientific and Technical Information of China (English)

    XUE Zheng-Yuan; YI You-Min; CAO Zhuo-Liang

    2005-01-01

    A scheme of teleportation of a tripartite state via W state is suggested. The W state serves as quantum channels. Standard Bell-state measurements and Von Neumann measurements are performed. After the sender operates the measurements and informs the receiver her results, he can reconstruct the original state by the corresponding unitary transformation. The probability of the successful teleportation is also obtained.

  2. Objectivity in a Noisy Photonic Environment through Quantum State Information Broadcasting

    Science.gov (United States)

    Korbicz, J. K.; Horodecki, P.; Horodecki, R.

    2014-03-01

    Recently, the emergence of classical objectivity as a property of a quantum state has been explicitly derived for a small object embedded in a photonic environment in terms of a spectrum broadcast form—a specific classically correlated state, redundantly encoding information about the preferred states of the object in the environment. However, the environment was in a pure state and the fundamental problem was how generic and robust is the conclusion. Here, we prove that despite the initial environmental noise, the emergence of the broadcast structure still holds, leading to the perceived objectivity of the state of the object. We also show how this leads to a quantum Darwinism-type condition, reflecting the classicality of proliferated information in terms of a limit behavior of the mutual information. Quite surprisingly, we find "singular points" of the decoherence, which can be used to faithfully broadcast a specific classical message through the noisy environment.

  3. Objectivity in a noisy photonic environment through quantum state information broadcasting.

    Science.gov (United States)

    Korbicz, J K; Horodecki, P; Horodecki, R

    2014-03-28

    Recently, the emergence of classical objectivity as a property of a quantum state has been explicitly derived for a small object embedded in a photonic environment in terms of a spectrum broadcast form-a specific classically correlated state, redundantly encoding information about the preferred states of the object in the environment. However, the environment was in a pure state and the fundamental problem was how generic and robust is the conclusion. Here, we prove that despite the initial environmental noise, the emergence of the broadcast structure still holds, leading to the perceived objectivity of the state of the object. We also show how this leads to a quantum Darwinism-type condition, reflecting the classicality of proliferated information in terms of a limit behavior of the mutual information. Quite surprisingly, we find "singular points" of the decoherence, which can be used to faithfully broadcast a specific classical message through the noisy environment.

  4. Information-Disturbance Tradeoff in Estimating the Unknown Three-Qubit GHZ State

    Institute of Scientific and Technical Information of China (English)

    ZHANG Sheng-Li; ZOU Xu-Bo; LI Ke; JIN Chen-Hui; GUO Guang-Can

    2007-01-01

    In a recent paper, Sacchi (Phys. Rev. Lett. 96 (2006) 220502) studied the information-disturbance tradeoff in estimating an unknown two-qubit maximally entangled state. In this study, we explore the tradeoff in estimating 13 an unknown three-qubit GHZ state. The optimal estimation process supplies a fidelity of 13/54 and the tradeoff interpolates smoothly between non-informative measurement and optimal estimation process.

  5. Preparation of multi-atom specially entangled W-class state and splitting quantum information

    Institute of Scientific and Technical Information of China (English)

    WANG YaHong; SONG HeShan

    2009-01-01

    We give a protocol to prepare specially entangled W-class state of multi-atom which can be used to exactly teleport an arbitrarily unknown two-level two-atom state.During the process,the quantum information is split into n parts and the original quantum information can be sent to anyone of the n recipients with the other n-1 recipients' collaboration.In addition,we will give a suggestion to realize this scheme via QED cavity.

  6. The States of Sub Saharan Africa on the way to the Global Information Society

    Directory of Open Access Journals (Sweden)

    Konstantin A. Pantserev

    2010-12-01

    Full Text Available The paper devotes to the problem of overcoming of the digital divide in the Sub Saharan African States. On the example of Kenya the author speaks about the comparative success of the development of the information technologies in Africa and in turn underlines the most significant obstacles on the way of African states to the global information society and suggests the means how to overcome them.

  7. Trap states extraction of p-channel SnO thin-film transistors based on percolation and multiple trapping carrier conductions

    Science.gov (United States)

    Qiang, Lei; Liu, Wuguang; Pei, Yanli; Wang, Gang; Yao, Ruohe

    2017-03-01

    A new method is proposed to extract the trap states in p-channel SnO thin-film transistors (TFTs). In this method, the dominant conduction mechanisms under different temperatures have been taken into account. There are percolation and multiple trapping conduction mechanisms. Combined with the drain current-temperature (Ids-T) and capacitance-voltage (C-V) measurements, the variation of trap states concentrations with the surface potential is derived. Results show that energy-dependent density of states (DOS) is in the order of 1019 eV/cm3. And the maximum of the density of states at the interface between the gate dielectric and the SnO channel is Nss = 1.77 × 1014 cm-2 eV-1.

  8. The interference effects of multi-channel pion-pion scattering contributions to the final states of $\\Psi$- and $\\Upsilon$-meson family decays

    CERN Document Server

    Surovtsev, Yu S; Gutsche, T; Kamiński, R; Lyubovitskij, V E; Nagy, M

    2016-01-01

    It is shown that the basic shape of dipion mass distributions in the two-pion transitions of both charmonia and bottomonia states are explained by an unified mechanism based on the contribution of the $\\pi\\pi$, $K\\overline{K}$ and $\\eta\\eta$ coupled channels including their interference.

  9. Benchmarking the State of Chuuk's Education Management Information System. REL 2017-176

    Science.gov (United States)

    Kendall, John S.; Dandapani, Nitara; Cicchinelli, Louis F.

    2016-01-01

    A quality data management system, such as an education management information system (EMIS), a state longitudinal data system, or a data warehouse, is key to ensuring that education policy, planning, and strategy decisions are grounded in accurate information (Data Quality Campaign, 2010; Mohamed, Kadir, May-Lin, Rahman, & Arshad, 2009;…

  10. Benchmarking the State of Kosrae's Education Management Information System. REL 2017-174

    Science.gov (United States)

    Kendall, John S.; Dandapani, Nitara; Cicchinelli, Louis F.

    2016-01-01

    A quality data management system, such as an education management information system (EMIS), a state longitudinal data system, or a data warehouse, is key to ensuring that education policy, planning, and strategy decisions are grounded in accurate information (Data Quality Campaign, 2010; Mohamed, Kadir, May-Lin, Rahman, & Arshad, 2009;…

  11. Benchmarking the State of Pohnpei's Education Management Information System. REL 2017-175

    Science.gov (United States)

    Kendall, John S.; Dandapani, Nitara; Cicchinelli, Louis F.

    2016-01-01

    A quality data management system, such as an education management information system (EMIS), a state longitudinal data system, or a data warehouse, is key to ensuring that education policy, planning, and strategy decisions are grounded in accurate information (Data Quality Campaign, 2010; Mohamed, Kadir, May-Lin, Rahman, & Arshad, 2009;…

  12. 76 FR 42735 - Comment Request for Information Collection for State Integrated Workforce Plan Requirements for...

    Science.gov (United States)

    2011-07-19

    ... Employment and Training Administration Comment Request for Information Collection for State Integrated... customer needs, deliver integrated user-friendly services, and are accountable to the customers and the... continuing collections of information in accordance with the Paperwork Reduction Act of 1995 (PRA95) ....

  13. 75 FR 409 - Privacy Act of 1974; United States Citizenship and Immigration Services-010 Asylum Information...

    Science.gov (United States)

    2010-01-05

    ...--010 Asylum Information and Pre-Screening System of Records AGENCY: Privacy Office; DHS. ACTION: Notice... Security's inventory, entitled Unites States Citizenship and Immigration Services-010 Asylum Information... systems: The Refugees, Asylum, and Parole System and the Asylum Pre-Screening System. Refugees,...

  14. 78 FR 77368 - Peanut Promotion, Research, and Information Order; Amendment to Primary Peanut-Producing States...

    Science.gov (United States)

    2013-12-23

    ... Agricultural Marketing Service 7 CFR Part 1216 Peanut Promotion, Research, and Information Order; Amendment to... primary peanut-producing State under the Peanut Promotion, Research, and Information Order (Order). The... or to the Promotion and Economics Division, Fruit and Vegetable Program, AMS, USDA, 1400...

  15. 76 FR 28625 - Sorghum Promotion, Research, and Information Program; State Referendum Results

    Science.gov (United States)

    2011-05-18

    ... Service 7 CFR 1221 Sorghum Promotion, Research, and Information Program; State Referendum Results AGENCY..., 2011, through February 28, 2011, have approved the continuation of the Sorghum Promotion, Research, and... Promotion, Research, and Information Act of 1996 (Act) (7 U.S.C. 7411-7425), the Department of...

  16. Sources of Malaria Information among Pregnant Women in Ebonyi State and Implications for Malaria Health Education

    Science.gov (United States)

    Amari-Omaka, Lois Nnenna; Obande-Ogbuinya, Nkiru Edith

    2016-01-01

    The purpose of this study was to determine sources of malaria information among pregnant women in Ebonyi state and implications for malaria education. The cross sectional research design was adopted and stratified sampling technique was used to select a total of five hundred and four (504) pregnant women from 12 hospitals in the state. A self…

  17. Leveraging the Power of State Longitudinal Data Systems: Building Capacity to Turn Data into Useful Information

    Science.gov (United States)

    Data Quality Campaign, 2011

    2011-01-01

    Faced with the need to create a competitive workforce and improve the quality of our education system, states are pursuing policy agendas to better prepare students for postsecondary education and careers. To inform these agendas, statewide longitudinal data systems (SLDSs) have become an invaluable asset and serve as a tool to help states answer…

  18. Immunization information systems--progress on integration of school nurses: a multi-state roundtable.

    Science.gov (United States)

    Galemore, Cynthia A

    2011-03-01

    The following is an article and roundtable discussion on school nurse integration into immunization information systems. The discussion participants were April Bailey, Deputy Director, Immunization Division, Indiana State Department of Health; Thomas Maerz, Manager, Wisconsin Immunization Registry; Erin Seward, Immunization Program Manager, Nevada State Health Division; and Debra Warren, Project Manager, KSWebIZ, Kansas Immunization Program.

  19. 75 FR 38595 - Guidance to States Regarding Driver History Record Information Security, Continuity of Operation...

    Science.gov (United States)

    2010-07-02

    ...The Federal Motor Carrier Safety Administration (FMCSA) announces guidance to State driver licensing agencies (SDLAs) to support their efforts at maintaining the security of information contained in the driver history record of commercial driver's license (CDL) holders. Further, FMCSA provides States with recommendations related to continuity of operation and disaster recovery planning to......

  20. 77 FR 76076 - Information Security Oversight Office; State, Local, Tribal, and Private Sector Policy Advisory...

    Science.gov (United States)

    2012-12-26

    ... RECORDS ADMINISTRATION Information Security Oversight Office; State, Local, Tribal, and Private Sector... Security Oversight Office. ACTION: Notice of meeting. SUMMARY: In accordance with the Federal Advisory... committee meeting of the State, Local, Tribal, and Private Sector Policy Advisory Committee. To discuss...

  1. 77 FR 69650 - Agency Information Collection Activities: Holders or Containers Which Enter the United States...

    Science.gov (United States)

    2012-11-20

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Holders or Containers... concerning the Holders or Containers which Enter the United States Duty Free. This request for comment is...: Title: Holders or Containers which Enter the United States Duty Free. OMB Number: 1651-0035. Form...

  2. MIMO-OC Scheme to Suppress Co-channel Interference

    Science.gov (United States)

    Zhang, Wei Jiong; Zhou, Xi Lang; Jin, Rong Hong

    In this letter, we present a multiple-input multiple-output (MIMO) optimal combining (OC) scheme based on alternate iteration. With the channel state information (CSI) of co-channel interferers (CCIs), this algorithm can be used in flat fading and frequency selective channels to suppress CCIs. Compared with the optimal transceiver of MIMO maximal ratio combining (MRC) systems, results of simulation show that this scheme improves the uplink transmission performance significantly.

  3. Quantum Multiple Access Channel

    Institute of Scientific and Technical Information of China (English)

    侯广; 黄民信; 张永德

    2002-01-01

    We consider the transmission of classical information over a quantum channel by many senders, which is a generalization of the two-sender case. The channel capacity region is shown to be a convex hull bound by the yon Neumann entropy and the conditional yon Neumann entropies. The result allows a reasonable distribution of channel capacity over the senders.

  4. Fluorescent Molecules as Transceiver Nanoantennas: The First Practical and High-Rate Information Transfer over a Nanoscale Communication Channel based on FRET

    OpenAIRE

    Murat Kuscu; Alper Kiraz; Akan, Ozgur B.

    2015-01-01

    Fluorescent Molecules as Transceiver Nanoantennas: The First Practical and High-Rate Information Transfer over a Nanoscale Communication Channel based on FRET Murat Kuscu1, Alper Kiraz2 & Ozgur B. Akan1 1Next-generation andWireless Communications Laboratory (NWCL), Department of Electrical and Electronics Engineering, Koc University, Istanbul, 34450, Turkey, 2Optofluidics and Nano-Optics Research Laboratory, Department of Physics, Koc University, Istanbul, 34450, Turke...

  5. Possible Realization of Cluster States and Quantum Information Transfer in Cavity QED via Raman Transition

    Institute of Scientific and Technical Information of China (English)

    ZHAN Zhi-Ming; LI Wei-Bin

    2007-01-01

    We present a scheme to generate cluster states with many atoms in cavity QED via Raman transition. In this scheme, no transfer of quantum information between the atoms and cavities is required, the cavity fields are only virtually excited and thus the cavity decay is suppressed during the generation of cluster states. The atoms are always populated in the two ground states. Therefore, the scheme is insensitive to the atomic spontaneous emission and cavity decay. We also show how to transfer quantum information from one atom to another.

  6. Efficient scheme for entangled states and quantum information transfer with trapped atoms in a resonator

    Institute of Scientific and Technical Information of China (English)

    Li Peng-Bo; Li Fu-Li

    2011-01-01

    A protocol is proposed to generate atomic entangled states and implement quantum information transfer in a cavity quantum electrodynamics system. It utilizes Raman transitions or stimulated Raman adiabatic passages between two systems to entangle the ground states of two three-state A-type atoms trapped in a single mode cavity. It does not need the measurements on cavity field nor atomic detection and can be implemented in a deterministic fashion. Since the present protocol is insensitive to both cavity decay and atomic spontaneous emission,it may have some interesting applications in quantum information processing.

  7. Majorization preservation of Gaussian bosonic channels

    Science.gov (United States)

    Jabbour, Michael G.; García-Patrón, Raúl; Cerf, Nicolas J.

    2016-07-01

    It is shown that phase-insensitive Gaussian bosonic channels are majorization-preserving over the set of passive states of the harmonic oscillator. This means that comparable passive states under majorization are transformed into equally comparable passive states by any phase-insensitive Gaussian bosonic channel. Our proof relies on a new preorder relation called Fock-majorization, which coincides with regular majorization for passive states but also induces another order relation in terms of mean boson number, thereby connecting the concepts of energy and disorder of a quantum state. The consequences of majorization preservation are discussed in the context of the broadcast communication capacity of Gaussian bosonic channels. Because most of our results are independent of the specific nature of the system under investigation, they could be generalized to other quantum systems and Hamiltonians, providing a new tool that may prove useful in quantum information theory and especially quantum thermodynamics.

  8. Extracting information about the initial state from the black hole radiation

    CERN Document Server

    Lochan, Kinjalk

    2015-01-01

    The crux of the black hole information paradox is related to the fact that the complete information about the initial state of a quantum field in a collapsing spacetime is not available to future asymptotic observers, belying the expectations from a unitary quantum theory. We study the imprints of the initial quantum state, contained in the distortions of the black hole radiation from the thermal spectrum, which can be detected by the asymptotic observers. We identify the class of in-states which can be fully reconstructed from the information contained in the distortions at the semiclassical level. Even for the general in-state, we can uncover a specific amount of information about the initial state. For a large class of initial states, some specific observables defined in the initial Hilbert space are completely determined from the resulting final spectrum. These results suggest that a \\textit{classical} collapse scenario ignores this richness of information in the resulting spectrum and a consistent quantu...

  9. Fisher information of a squeezed-state interferometer with a finite photon-number resolution

    CERN Document Server

    Liu, P; Yang, W; Jin, G R; Sun, C P

    2016-01-01

    Squeezed-state interferometry plays an important role in quantum-enhanced optical phase estimation, as it allows the estimation precision to be improved up to the Heisenberg limit by using ideal photon-number-resolving detectors at the output ports. Here we show that for each individual $N$% -photon component of the phase-matched coherent $\\otimes $ squeezed vacuum input state, the classical Fisher information always saturates the quantum Fisher information. Moreover, the total Fisher information is the sum of the contributions from each individual $N$-photon components, where the largest $N$ is limited by the finite number resolution of available photon counters. Based on this observation, we provide approximate formula that quantifies the amount of lost information due to the finite photon number resolution, e.g., given the mean photon number $\\bar{n}$ in the input state, $96$ percent of the Heisenberg limit can be achieved with the number resolution $\\gtrsim 5\\bar{n}$.

  10. Information about the state of a charge qubit gained by a weakly coupled quantum point contact

    Energy Technology Data Exchange (ETDEWEB)

    Ashhab, S; You, J Q; Nori, Franco [Advanced Science Institute, Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-0198 (Japan)], E-mail: ashhab@riken.jp

    2009-12-15

    We analyze the information that one can learn about the state of a quantum two-level system, i.e. a qubit, when probed weakly by a nearby detector. We consider the general case where the qubit Hamiltonian and the qubit's operator probed by the detector do not commute. Because the qubit's state keeps evolving while being probed and the measurement data is mixed with a detector-related background noise, one might expect the detector to fail in this case. We show, however, that under suitable conditions and by proper analysis of the measurement data, useful information about the initial state of the qubit can be extracted. Our approach complements the usual master-equation and quantum-trajectory approaches, which describe the evolution of the qubit's quantum state during the measurement process but do not keep track of the acquired measurement information.

  11. Information Technology of Study of the State Foreign Debt in Developing Countries

    Directory of Open Access Journals (Sweden)

    Matvieieva Iuliia M.

    2014-03-01

    Full Text Available Due to expansion of international relations, growth of interest of states in attraction of foreign capital, appearance of excessive debts and problems connected with them, urgency of the issue of the state foreign debt significantly increased. The problem of state foreign debt is especially sharp in developing countries. Taking into account specific features of functioning of economies of these states, it is necessary to develop information approaches with the aim of studying macro-economic processes, which could assist in creation of improved mechanisms of functioning of the debt policy. The goal of the article is building an information technology of study of the state foreign debt, which would allow conduct of a complex analysis of the studied problem. The article offers a three-stage information technology of study of the state foreign debt, which gives a possibility to analyse and assess the study problem. This article also reveals properties, functions and tasks, which are solve by the information technology. It gives a detailed description of each stage and its notional elements. It forms the structured database for a possibility to carry out an experiment. On the basis of the first stage the article builds econometric models, which reflect interrelations between macro-economic factors, which gives an opportunity to forecast, analyse and assess the state foreign debt.

  12. New Jersey state information handbook: Formerly Utilized Sites Remedial Action Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-10-31

    Under the implied authority of the Atomic Energy Act of 1954, as amended, radiological surveys and research work has been conducted to determine radiological conditions at former MED/AEC sites. As of this time, 31 sites in 13 states have been identified that require or may require remedial action. This volume is one of a series produced under contract with DOE, Office of Nuclear Waste Management, by POLITECH CORPORATION to develop a legislative and regulatory data base to assist the FUSRAP management in addressing the institutional and socioeconomic issues involved in carrying out the Remedial Action Program. This Information Handbook series contains information about all relevant government agencies at the Federal and state levels, the pertinent programs they administer, each affected state legislature, and current Federal and state legislative and regulatory initiatives. This volume is a compilation of information about the state of New Jersey. It contains: a description of the state executive branch structure; a summary of relevant state statutes and regulations; a description of the structure of the state legislature, identification of the officers and committee chairmen, and a summary of recent relevant legislative action; and the full text of relevant statutes and regulations. The loose-leaf format used in these volumes will allow the material to be updated periodically as the Remedial Action Program progresses.

  13. Study on the Communication Channels of Financial Information in Colleges and Universities%高校财务信息的传播渠道探讨

    Institute of Scientific and Technical Information of China (English)

    刘华坤

    2016-01-01

    One of the important contents in colleges and universities information disclosure is the financial information. In view of the characteristics of public or directional open financial information in colleges and universities, as well as the use of the financial information, three types of communication channels are analyzed. This paper also puts forward the com-munication channels of the financial information in colleges and universities under the triple play environment.%高校财务信息是高校信息公开的重要内容之一。针对高校完全公开类财务信息和指向性公开类财务信息的特点,以及高校财务信息的使用对象,分析高校财务信息的三类传播渠道,并提出三网融合信息环境下高校财务信息的传播渠道选择。

  14. Information Management System for the California State Water Resources Control Board (SWRCB)

    Science.gov (United States)

    Heald, T. C.; Redmann, G. H.

    1973-01-01

    A study was made to establish the requirements for an integrated state-wide information management system for water quality control and water quality rights for the State of California. The data sources and end requirements were analyzed for the data collected and used by the numerous agencies, both State and Federal, as well as the nine Regional Boards under the jurisdiction of the State Board. The report details the data interfaces and outlines the system design. A program plan and statement of work for implementation of the project is included.

  15. Decoherence-Free Quantum Information Processing with Four-Photon Entangled States

    CERN Document Server

    Bourennane, M; Gaertner, S; Kurtsiefer, C; Cabello, A; Weinfurter, H; Bourennane, Mohamed; Eibl, Manfred; Gaertner, Sascha; Kurtsiefer, Christian; Cabello, Adan; Weinfurter, Harald

    2004-01-01

    Decoherence-free states protect quantum information from collective noise, the predominant cause of decoherence in current implementations of quantum communication and computation. Here we demonstrate that spontaneous parametric down-conversion can be used to generate four-photon states which enable the encoding of one qubit in a decoherence-free subspace. The immunity against noise is verified by quantum state tomography of the encoded qubit. We show that particular states of the encoded qubit can be distinguished by local measurements on the four photons only.

  16. Potential Ramifications of Common Core State Standards Adoption on Information Literacy

    Directory of Open Access Journals (Sweden)

    Jacob Paul Eubanks

    2014-07-01

    Full Text Available In the United States, the decline in jobs for high school educated workers and the proliferation of jobs for post-secondary educated workers is driving the development of the Common Core State Standards. The Common Core State Standards theoretically shift K-12 pedagogy towards ability development of critical and extended thinking skills, preparing high school graduates for college and career readiness. This literature review explores the reasoning behind the shift to the Common Core State Standards and asks questions regarding the potential ramifications their adoption might have on post-secondary information literacy instruction.

  17. The capacity of the cascaded fading channel in the low power regime

    KAUST Repository

    Benkhelifa, Fatma

    2014-04-01

    In this paper, we present a simple way to compute the ergodic capacity of cascaded channels with perfect channel state information at both the transmitter and the receiver. We apply our generic results to the Rayleigh-double fading channel, and to the free-space optical channel in the presence of pointing errors and we express their low signal-to-noise ratio capacities. We mainly focus on the low signal-to-noise ratio range.

  18. 76 FR 71600 - Renewal of Agency Information Collection for Class III Tribal-State Gaming Compact Process...

    Science.gov (United States)

    2011-11-18

    ... Bureau of Indian Affairs Renewal of Agency Information Collection for Class III Tribal- State Gaming... collection of information for the Class III Tribal State Gaming Compact Process. The information collection... renewal of the approval for the information collection conducted under 25 CFR 293, Class III Tribal...

  19. State-dependent block of rat Nav1.4 sodium channels expressed in xenopus oocytes by pyrazoline-type insecticides.

    Science.gov (United States)

    Silver, Kristopher; Soderlund, David M

    2005-06-01

    Insecticidal pyrazolines inhibit voltage-sensitive sodium channels of both insect and mammalian neurons in a voltage-dependent manner. Studies on the effects of pyrazoline insecticides on mammalian sodium channels have been limited to experimentation on the tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) sodium channel populations of rat dorsal root ganglion (DRG) neurons. In this study, we examined the effects of the insecticidal pyrazolines indoxacarb, the N-decarbomethoxyllated metabolite of indoxacarb (DCJW), and RH 3421 on rat Na(v)1.4 sodium channels expressed in Xenopus laevis oocytes using the two-electrode voltage clamp technique. Both DCJW and RH 3421 were ineffective inhibitors of rat Na(v)1.4 sodium channels at a membrane potential of -120 mV, but depolarization to -60 mV or -30 mV during insecticide exposure resulted in substantial block. Inhibition by pyrazoline insecticides was nearly irreversible with washout, but repolarization of the membrane relieved block. DCJW and RH 3421 also caused hyperpolarizing shifts in the voltage dependence of slow inactivation without affecting the voltage dependence of activation or fast inactivation. These results suggest that DCJW and RH 3421 interact specifically with the slow inactivated state of the sodium channel. Indoxacarb did not cause block at any potential, yet it interfered with the ability of DCJW, but not RH 3421, to inhibit sodium current. Phenytoin, an anticonvulsant, reduced the efficacy of both DCJW and RH 3421. These data imply that the binding site for pyrazoline insecticides overlaps with that for therapeutic sodium channel blockers.

  20. Effects of fractal gating of potassium channels on neuronal behaviours

    Science.gov (United States)

    Zhao, De-Jiang; Zeng, Shang-You; Zhang, Zheng-Zhen

    2010-10-01

    The classical model of voltage-gated ion channels assumes that according to a Markov process ion channels switch among a small number of states without memory, but a bunch of experimental papers show that some ion channels exhibit significant memory effects, and this memory effects can take the form of kinetic rate constant that is fractal. Obviously the gating character of ion channels will affect generation and propagation of action potentials, furthermore, affect generation, coding and propagation of neural information. However, there is little previous research on this series of interesting issues. This paper investigates effects of fractal gating of potassium channel subunits switching from closed state to open state on neuronal behaviours. The obtained results show that fractal gating of potassium channel subunits switching from closed state to open state has important effects on neuronal behaviours, increases excitability, rest potential and spiking frequency of the neuronal membrane, and decreases threshold voltage and threshold injected current of the neuronal membrane. So fractal gating of potassium channel subunits switching from closed state to open state can improve the sensitivity of the neuronal membrane, and enlarge the encoded strength of neural information.

  1. Quantum feedback channels

    CERN Document Server

    Bowen, G

    2002-01-01

    In classical information theory the capacity of a noisy communication channel cannot be increased by the use of feedback. In quantum information theory the no-cloning theorem means that noiseless copying and feedback of quantum information cannot be achieved. In this paper, quantum feedback is defined as the unlimited use of a noiseless quantum channel from receiver to sender. Given such quantum feedback, it is shown to provide no increase in the entanglement-assisted capacities of a noisy quantum channel, in direct analogy to the classical case. It is also shown that in various cases of non-assisted capacities, feedback can increase the capacity of many quantum channels.

  2. Research on selecting the sale channel model of the information goods%信息产品销售渠道模式选择研究

    Institute of Scientific and Technical Information of China (English)

    刘志勇; 李敏强; 寇纪淞

    2013-01-01

    The information goods manufacturer can distribute their products through many kinds of channels, e.g. online direct sale and traditional retail marketing. The retailer pays a manufacturer based on two common payment schemes, the Fixed-fee policy and the Per-copy policy. Which channel and sell model is preferable for the manufacture? The product quality, the price, and the customer acceptance for direct channel are the decisive factors. Through analyzing the decision behaviors of the manufacture, retailer and consumer, the model of maximizing the manufacture's profit is presented in the presence of both direct and retail channel. Based on the comparison among different channels, the paper shows that when the valuation for the information goods has a uniform distribution, the manufacture prefers the Fixed-fee policy through the direct sale channel, whereas the Per-copy policy is preferable through dual-channel. The best sale channel strategy is to distribute the high-quality version through the direct sale channel and the low-quality version through the retailing channel for the manufacturer.%信息产品供应商在销售产品时有多种渠道可以选择,可以通过在线直销,也可以通过传统的零售渠道方式.而在零售模式下,供应商可以与零售商之间采用Fixed-fee协议或Per-copy协议.供应商在面临这些不同的销售渠道和销售方式时,产品质量、销售价格以及消费者对直销渠道的接受程度等因素决定了最终的选择方式.通过对供应商、零售商和消费者的决策行为进行分析,给出了供应商通过直销渠道和零售渠道销售产品下的收益最优化模型,并对结果进行了比较.研究表明当消费者对产品评价值服从均匀分布的情况时,零售渠道下采用Fixed-fee模式有利于供应商,而在双重渠道下,供应商采用Per-copy模式更有利.而且当供应商采用直销渠道销售高质量产品,由零售渠道销售较低质量产品时,供应商能获得最大收益.

  3. Three-body analysis of 11Li and its -decay to deuteron channel and to halo analog state 11Be* (18.3 MeV)

    Indian Academy of Sciences (India)

    S Kumar; V S Bhasin

    2004-09-01

    The ground state wave function of 11Li obtained in a three-body model proposed earlier (S Kumar and V S Bhasin, Phys. Rev. C65, 034007 (2002)) has been employed to study the probability distributions, momentum distributions and n–n correlation. Complex scaling method has been used to find the energy positions and widths of the three resonant states of 11Li above the breakup threshold. The formalism is extended further to study the -decay of 11Li to two channels. One is the -transition of 11Li into a high lying excited state of 11Be at 18.3 MeV, i.e., 11Be* and the second is the decay to deuteron + 9Li channel. The 11Be* state has been considered as a halo analog state identified as a bound three-body (9Li + n + p) system. The n- 9Li interaction in-corporates both the virtual state and the p-wave resonance observed experimentally. For p- 9Li interaction, a Coulomb corrected separable interaction is constructed using charge indepedendence for strong interaction part. The n–p interaction is operative only in 3S1 state corresponding to the isotopic spin h = 0. As a result the 11Be* state has the same isotopic spin as that of 9Li core, i.e., = 3/2. Using these realistic parameters as input and without invoking any other free parameter, the model has been used to predict the strength of the Gamow–Teller -decay of 11Li to 11Be* , i.e., GT = 1.5 and the value of the branching ratio to 9Li + deuteron channel to be 1.3 × 10−4. These results are found to be in rather good agreement with the recent experimental findings.

  4. Secrecy Capacity over Correlated Ergodic Fading Channel

    CERN Document Server

    Jeon, Hyoungsuk; Kim, Minki; Lee, Hyuckjae; Ha, Jeongseok

    2008-01-01

    We investigate the secrecy capacity of an ergodic fading wiretap channel in which the main channel is correlated with the eavesdropper channel. In this study, the full Channel State Information (CSI) is assumed, and thus the transmitter knows the channel gains of the legitimate receiver and the eavesdropper. By analyzing the resulting secrecy capacity we quantify the loss of the secrecy capacity due to the correlation. In addition, we study the asymptotic behavior of the secrecy capacity as Signal-to-Noise Ratio (SNR) tends to infinity. The capacity of an ordinary fading channel logarithmically increases with SNR. On the contrary, the secrecy capacity converges into a limit which can be an upper bound on the secrecy capacity over the fading wiretap channel. We find a closed form of the upper bound for the correlated Rayleigh wiretap channel which also includes the independent case as a special one. Our work shows that the upper bound is determined by only two channel parameters; the correlation coefficient an...

  5. Quantum channels and memory effects

    Science.gov (United States)

    Caruso, Filippo; Giovannetti, Vittorio; Lupo, Cosmo; Mancini, Stefano

    2014-10-01

    Any physical process can be represented as a quantum channel mapping an initial state to a final state. Hence it can be characterized from the point of view of communication theory, i.e., in terms of its ability to transfer information. Quantum information provides a theoretical framework and the proper mathematical tools to accomplish this. In this context the notion of codes and communication capacities have been introduced by generalizing them from the classical Shannon theory of information transmission and error correction. The underlying assumption of this approach is to consider the channel not as acting on a single system, but on sequences of systems, which, when properly initialized allow one to overcome the noisy effects induced by the physical process under consideration. While most of the work produced so far has been focused on the case in which a given channel transformation acts identically and independently on the various elements of the sequence (memoryless configuration in jargon), correlated error models appear to be a more realistic way to approach the problem. A slightly different, yet conceptually related, notion of correlated errors applies to a single quantum system which evolves continuously in time under the influence of an external disturbance which acts on it in a non-Markovian fashion. This leads to the study of memory effects in quantum channels: a fertile ground where interesting novel phenomena emerge at the intersection of quantum information theory and other branches of physics. A survey is taken of the field of quantum channels theory while also embracing these specific and complex settings.

  6. Crimes against Information Security: International Legal Aspects of Fighting and Experience of Some States

    Directory of Open Access Journals (Sweden)

    MARINA ALEKSANDROVNA EFREMOVA

    2016-04-01

    Full Text Available This article is devoted to the study of foreign criminal law providing for liability for information security offences. The relevance of that problem is driven by the intensifying IT development and globalization, under which both information security of a separate state and international information security may not be achieved by the efforts of a single state. Efforts need to be consolidated, and a uniform approach to the solution of that matter needs to be worked out. The author stresses that in the Russian Federation and in most foreign countries there is no systematic approach to criminal law protection of information security except for the Republic of Poland. In most foreign criminal codes JIBC April 2016, Vol. 21, No.S3 - 2 - (CC, the provisions on information security protection are spread all over Special parts. In most foreign countries, offences against confidentiality of professional and official secrets are criminalized, while in the Civil Code of the RF such provisions are missing. Meantime, foreign criminal law does not specify separate elements of crimes in order to protect tax secrets. Criminal law protection of state secret is solved differently in foreign countries: via detailed regulation for state secret offences and under totally missing respective provisions in CC. Regarding cybercrime, the CIS countries used to apply the uniform approach to criminalization of respective elements of crime as criminal laws of most of them adopted the provisions of Model Criminal Code of the CIS member states. However, in future, due to the amendments of articles providing for liability for cybercrime that approach was lost. In foreign countries, along with the traditional illegal access to computer information, the liability is provided for computer sabotage, computer fraud. The author opines that a systematic approach is required to criminal law protection both in the Russian Federation and in foreign countries. Only uniform, joint

  7. Restructuring consciousness -the psychedelic state in light of integrated information theory.

    Science.gov (United States)

    Gallimore, Andrew R

    2015-01-01

    The psychological state elicited by the classic psychedelics drugs, such as LSD and psilocybin, is one of the most fascinating and yet least understood states of consciousness. However, with the advent of modern functional neuroimaging techniques, the effect of these drugs on neural activity is now being revealed, although many of the varied phenomenological features of the psychedelic state remain challenging to explain. Integrated information theory (IIT) is one of the foremost contemporary theories of consciousness, providing a mathematical formalization of both the quantity and quality of conscious experience. This theory can be applied to all known states of consciousness, including the psychedelic state. Using the results of functional neuroimaging data on the psychedelic state, the effects of psychedelic drugs on both the level and structure of consciousness can be explained in terms of the conceptual framework of IIT. This new IIT-based model of the psychedelic state provides an explanation for many of its phenomenological features, including unconstrained cognition, alterations in the structure and meaning of concepts and a sense of expanded awareness. This model also suggests that whilst cognitive flexibility, creativity, and imagination are enhanced during the psychedelic state, this occurs at the expense of cause-effect information, as well as degrading the brain's ability to organize, categorize, and differentiate the constituents of conscious experience. Furthermore, the model generates specific predictions that can be tested using a combination of functional imaging techniques, as has been applied to the study of levels of consciousness during anesthesia and following brain injury.

  8. Restructuring consciousness –the psychedelic state in light of integrated information theory

    Science.gov (United States)

    Gallimore, Andrew R.

    2015-01-01

    The psychological state elicited by the classic psychedelics drugs, such as LSD and psilocybin, is one of the most fascinating and yet least understood states of consciousness. However, with the advent of modern functional neuroimaging techniques, the effect of these drugs on neural activity is now being revealed, although many of the varied phenomenological features of the psychedelic state remain challenging to explain. Integrated information theory (IIT) is one of the foremost contemporary theories of consciousness, providing a mathematical formalization of both the quantity and quality of conscious experience. This theory can be applied to all known states of consciousness, including the psychedelic state. Using the results of functional neuroimaging data on the psychedelic state, the effects of psychedelic drugs on both the level and structure of consciousness can be explained in terms of the conceptual framework of IIT. This new IIT-based model of the psychedelic state provides an explanation for many of its phenomenological features, including unconstrained cognition, alterations in the structure and meaning of concepts and a sense of expanded awareness. This model also suggests that whilst cognitive flexibility, creativity, and imagination are enhanced during the psychedelic state, this occurs at the expense of cause-effect information, as well as degrading the brain's ability to organize, categorize, and differentiate the constituents of conscious experience. Furthermore, the model generates specific predictions that can be tested using a combination of functional imaging techniques, as has been applied to the study of levels of consciousness during anesthesia and following brain injury. PMID:26124719

  9. Usefulness of multiqubit W-type states in quantum information processing

    Science.gov (United States)

    Singh, P.; Adhikari, S.; Kumar, A.

    2016-10-01

    We analyze the efficiency of multiqubit W-type states as resources for quantum information. For this, we identify and generalize four-qubit W-type states. Our results show that these states can be used as resources for deterministic quantum information processing. The utility of results, however, is limited by the availability of experimental setups to perform and distinguish multiqubit measurements. We therefore emphasize protocols where two users want to establish an optimal bipartite entanglement using the partially entangled W-type states. We find that for such practical purposes, four-qubit W-type states can be a better resource in comparison to three-qubit W-type states. For a dense coding protocol, our states can be used deterministically to send two bits of classical message by locally manipulating a single qubit. In addition, we also propose a realistic experimental method to prepare the four-qubit W-type states using standard unitary operations and weak measurements.

  10. Management of Information and Infrastructure of Indigenous Community at Royal Belum State Park Using Geographical Information System: A Conceptual Design

    Directory of Open Access Journals (Sweden)

    Othman Zainon

    2015-07-01

    Full Text Available Abstract. Nowadays, an integrated location, descriptive inventory data and geographical information are required for a better decision making in Indigenous community management activities. The management system can improve productivity and to save time, money and man power. Conventional maps and Indigenous inventories on papers or spread sheet are lack of meeting these requirements which are not static and subjected to change rapidly. The Geographic Information Systems (GIS and Database Management (DBM System are capabilities and confined in manipulation of location and descriptive data, respectively. A GIS system is chosen in Management Information and Infrastructure of Indigenous Communities because its meets all the requirements that can help the authorities to managed the community. GIS able to manipulate location and descriptive data as well as the relationships between them are dynamic. This paper will discussed briefly the conceptual design of GIS activities and Indigenous community in Royal Belum State Park, Malaysia, then terminology and theoretical concepts of GIS, Indigenous community management and the link between them are reviewed.Keywords:  Management, information, infrastructure, conceptual design, Indigenous community 

  11. Management of Information and Infrastructure of Indigenous Community at Royal Belum State Park Using Geographical Information System: A Conceptual Design

    Directory of Open Access Journals (Sweden)

    Othman Zainon

    2015-06-01

    Full Text Available Abstract. Nowadays, an integrated location, descriptive inventory data and geographical information are required for a better decision making in Indigenous community management activities. The management system can improve productivity and to save time, money and man power. Conventional maps and Indigenous inventories on papers or spread sheet are lack of meeting these requirements which are not static and subjected to change rapidly. The Geographic Information Systems (GIS and Database Management (DBM System are capabilities and confined in manipulation of location and descriptive data, respectively. A GIS system is chosen in Management Information and Infrastructure of Indigenous Communities because its meets all the requirements that can help the authorities to managed the community. GIS able to manipulate location and descriptive data as well as the relationships between them are dynamic. This paper will discussed briefly the conceptual design of GIS activities and Indigenous community in Royal Belum State Park, Malaysia, then terminology and theoretical concepts of GIS, Indigenous community management and the link between them are reviewed. Keywords: Management, information, infrastructure, conceptual design, Indigenous community

  12. Influencing Tomorrow: A Study of Emerging Influence Techniques and Their Relevance to United States Information Operations

    Science.gov (United States)

    2015-06-12

    adaptation of influence techniques to keep pace and exploit changing methods of communication. The internet, cellular communication, and social media has...is to achieve a massing of information in order to create a spike or trend and gain the attention of larger audiences. This technique is most...INFLUENCING TOMORROW: A STUDY OF EMERGING INFLUENCE TECHNIQUES AND THEIR RELEVANCE TO UNITED STATES INFORMATION OPERATIONS A

  13. Transfer of entangled state, entanglement swapping and quantum information processing via the Rydberg blockade

    Institute of Scientific and Technical Information of China (English)

    Deng Li; Chen Ai-Xi; Zhang Jian-Song

    2011-01-01

    We provide a scheme with which the transfer of the entangled state and the entanglement swapping can be realized in a system of neutral atoms via the Rydberg blockade.Our idea can be extended to teleport an unknown atomic state.According to the latest theoretical research of the Rydberg excitation and experimental reports of the Rydberg blockade effect in quantum information processing,we discuss the experimental feasibility of our scheme.

  14. BLIND CHANNEL ESTIMATION OF SPACE-TIME FREQUENCY-SHIFT KEYING

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The decoupled coherent Maximum Likelihood (ML) detection algorithm presented in this lettercan sharply reduce the complexity of the receiver as well as provide better error performance under the pre-condition that channel should be estimated first. Considering the bandwidth inefficiency of Frequency ShiftKeying (FSK), the acquisition of channel state information through training sequences will further decreasethe transmission efficiency. This letter presents a blind channel estimation algorithm based on noise subspacetheory which can acquire channel information without any training symbols. The simulation shows that thealgorithm brings about fewer channel estimation errors while the frequency efficiency can be increased.

  15. Degenerated-Inverse-Matrix-Based Channel Estimation for OFDM Systems

    Directory of Open Access Journals (Sweden)

    Makoto Yoshida

    2009-01-01

    Full Text Available This paper addresses time-domain channel estimation for pilot-symbol-aided orthogonal frequency division multiplexing (OFDM systems. By using a cyclic sinc-function matrix uniquely determined by Nc transmitted subcarriers, the performance of our proposed scheme approaches perfect channel state information (CSI, within a maximum of 0.4 dB degradation, regardless of the delay spread of the channel, Doppler frequency, and subcarrier modulation. Furthermore, reducing the matrix size by splitting the dispersive channel impulse response into clusters means that the degenerated inverse matrix estimator (DIME is feasible for broadband, high-quality OFDM transmission systems. In addition to theoretical analysis on normalized mean squared error (NMSE performance of DIME, computer simulations over realistic nonsample spaced channels also showed that the DIME is robust for intersymbol interference (ISI channels and fast time-invariant channels where a minimum mean squared error (MMSE estimator does not work well.

  16. Encoding of social state information by neuronal activities in the macaque caudate nucleus.

    Science.gov (United States)

    Santos, Gustavo S; Nagasaka, Yasuo; Fujii, Naotaka; Nakahara, Hiroyuki

    2012-01-01

    Social animals adjust their behavior according to social relationships and momentary circumstances. Dominant-submissive relationships modulate, but do not completely determine, their competitive behaviors. For example, a submissive monkey's decision to retrieve food depends not only on the presence of dominant partners but also on their observed behavior. Thus, behavioral expression requires a dynamic evaluation of reward outcome and momentary social states. The neural mechanisms underlying this evaluation remain elusive. The caudate nucleus (CN) plays a pivotal role in representing reward expectation and translating it into action selection. To investigate whether their activities encode social state information, we recorded from CN neurons in monkeys while they performed a competitive food-grab task against a dominant competitor. We found two groups of CN neurons: one primarily responded to reward outcome, while the other primarily tracked the monkey's social state. These social state-dependent neurons showed greater activity when the monkeys freely retrieved food without active challenges from the competitor and reduced activity when the monkeys were in a submissive state due to the competitor's active behavior. These results indicate that different neuronal activities in the CN encode social state information and reward-related information, which may contribute to adjusting competitive behavior in dynamic social contexts.

  17. Information and backaction due to phase contrast imaging measurements of cold atomic gases: beyond Gaussian states

    CERN Document Server

    Ilo-Okeke, Ebubechukwu O

    2016-01-01

    We further examine a theory of phase contrast imaging (PCI) of cold atomic gases, first introduced by us in Phys. Rev. Lett. {\\bf 112}, 233602 (2014). We model the PCI measurement by directly calculating the entangled state between the light and the atoms due to the ac Stark shift, which induces a conditional phase shift on the light depending upon the atomic state. By interfering the light that passes through the BEC with the original light, one can obtain information of the atomic state at a single shot level. We derive an exact expression for a measurement operator that embodies the information obtained from PCI, as well as the back-action on the atomic state. By the use of exact expressions for the measurement process, we go beyond the continuous variables approximation such that the non-Gaussian regime can be accessed for both the measured state and the post-measurement state. Features such as the photon probability density, signal, signal variance, Fisher information, error of the measurement, and the b...

  18. [Adoption of information and communication technologies in the dialysis clinics of Bahia State].

    Science.gov (United States)

    Mota, Fábio Batista; Ferreira Júnior, Hamilton de Moura

    2010-06-01

    The aim of this article is to investigate the adoption and use of information and communication technologies within private dialysis clinics in Bahia State. A case study was developed with companies by applying, to clinics' managerial teams, a research questionnaire adapted from RedeSist and from PINTEC. The sample included 20 companies, listed by CNES of the Ministry of Health, and obtained a positive usage rate data of 60%. The collected quantitative information was analyzed by interviewees' answer frequency distribution. Conclusion indicates that the adoption of information and communication technologies by the clinics is not directly related to their access to these technologies but to the under usage of their economical potential.

  19. Thermodynamic and kinetic properties of amino-terminal and S4-S5 loop HERG channel mutants under steady-state conditions.

    Science.gov (United States)

    Alonso-Ron, Carlos; de la Peña, Pilar; Miranda, Pablo; Domínguez, Pedro; Barros, Francisco

    2008-05-15

    Gating kinetics and underlying thermodynamic properties of human ether-a-go-go-related gene (HERG) K(+) channels expressed in Xenopus oocytes were studied using protocols able to yield true steady-state kinetic parameters. Channel mutants lacking the initial 16 residues of the amino terminus before the conserved eag/PAS region showed significant positive shifts in activation voltage dependence associated with a reduction of z(g) values and a less negative DeltaG(o), indicating a deletion-induced displacement of the equilibrium toward the closed state. Conversely, a negative shift and an increased DeltaG(o), indicative of closed-state destabilization, were observed in channels lacking the amino-terminal proximal domain. Furthermore, accelerated activation and deactivation kinetics were observed in these constructs when differences in driving force were considered, suggesting that the presence of distal and proximal amino-terminal segments contributes in wild-type channels to specific chemical interactions that raise the energy barrier for activation. Steady-state characteristics of some single point mutants in the intracellular loop linking S4 and S5 helices revealed a striking parallelism between the effects of these mutations and those of the amino-terminal modifications. Our data indicate that in addition to the recognized influence of the initial amino-terminus region on HERG deactivation, this cytoplasmic region also affects activation behavior. The data also suggest that not only a slow movement of the voltage sensor itself but also delaying its functional coupling to the activation gate by some cytoplasmic structures possibly acting on the S4-S5 loop may contribute to the atypically slow gating of HERG.

  20. The state of information and communication technology and health informatics in ghana.

    Science.gov (United States)

    Achampong, Emmanuel Kusi

    2012-01-01

    Information and Communication Technology (ICT) has become a major tool in delivery of health services and has had an innovative impact on quality of life. ICT is affecting the way healthcare is delivered to clients. In this paper, we discuss the state of ICT and health informatics in Ghana. We also discuss the state of various relevant infrastructures for the successful implementation of ehealth projects. We analyse the past and present state of health informatics in Ghana, in comparison to other African countries. We also review the challenges facing successful implementation of health informatics projects in Ghana and suggest possible solutions.

  1. Quantum broadcast channels

    CERN Document Server

    Yard, J; Devetak, I; Yard, Jon; Hayden, Patrick; Devetak, Igor

    2006-01-01

    We analyze quantum broadcast channels, which are quantum channels with a single sender and many receivers. Focusing on channels with two receivers for simplicity, we generalize a number of results from the network Shannon theory literature which give the rates at which two senders can receive a common message, while a personalized one is sent to one of them. Our first collection of results applies to channels with a classical input and quantum outputs. The second class of theorems we prove concern sending a common classical message over a quantum broadcast channel, while sending quantum information to one of the receivers. The third group of results we obtain concern communication over an isometry, giving the rates at quantum information can be sent to one receiver, while common quantum information is sent to both, in the sense that tripartite GHZ entanglement is established. For each scenario, we provide an additivity proof for an appropriate class of channels, yielding single-letter characterizations of the...

  2. State of the art/science: Visual methods and information behavior research

    DEFF Research Database (Denmark)

    Hartel, Jenna; Sonnenwald, Diane H.; Lundh, Anna;

    2012-01-01

    This panel reports on methodological innovation now underway as information behavior scholars begin to experiment with visual methods. The session launches with a succinct introduction to visual methods by Jenna Hartel and then showcases three exemplar visual research designs. First, Dianne...... will have gained: knowledge of the state of the art/science of visual methods in information behavior research; an appreciation for the richness the approach brings to the specialty; and a platform to take new visual research designs forward....... Sonnenwald presents the "information horizon interview" (1999, 2005), the singular visual method native to the information behavior community. Second, Anna Lundh (2010) describes her techniques for capturing and analyzing primary school children's information activities utilizing video recordings. Third...

  3. Wehrl information entropy and phase distributions of Schrodinger cat and cat-like states

    CERN Document Server

    Miranowicz, A; Wahiddin, M R B; Imoto, N

    2001-01-01

    The Wehrl information entropy and its phase density, the so-called Wehrl phase distribution, are applied to describe Schr\\"odinger cat and cat-like (kitten) states. The advantages of the Wehrl phase distribution over the Wehrl entropy in a description of the superposition principle are presented. The entropic measures are compared with a conventional phase distribution from the Husimi Q-function. Compact-form formulae for the entropic measures are found for superpositions of well-separated states. Examples of Schr\\"odinger cats (including even, odd and Yurke-Stoler coherent states), as well as the cat-like states generated in Kerr medium are analyzed in detail. It is shown that, in contrast to the Wehrl entropy, the Wehrl phase distribution properly distinguishes between different superpositions of unequally-weighted states in respect to their number and phase-space configuration.

  4. Network Channel Information Monitoring of Conflict Resolution Technology Research%网络信道信息监听中的冲突消除技术研究

    Institute of Scientific and Technical Information of China (English)

    兰诗梅

    2012-01-01

    研究网络信道信息监听冲突消除方法.在信息监听过程中,当同一信道内同时接收到不同方向的信息时,将造成信息监听冲突,导致无法准确监听信息.为了避免上述缺陷,提出了一种基于信号排队延时算法的监听冲突消除技术.利用多时间间隔冲突预测方法,预测网络信道中的监听信号冲突.利用信号排队延时方法,对监听信号进行排序,从而实现网络信道中信息监听冲突的消除.实验结果表明,这种算法能够有效消除网络信道中的信息监听冲突,提高了信息监听的准确性.%Research conflict resolution of network information monitoring. There exist information conflicts in the same channel during the monitor process. This paper put forward a monitor conflict resolution technology based on signal queuing delay algorithm. This algorithm uses mulli - interval conflict prediction method to predict network monitor signal channel conflicts. The method sorts the monitor signals through signal queuing delay method in order to e-liminate the conflict of listening information in the channel,The experiment results show that the algorithm can eliminate monitor conflict and improve the accuracy of identification.

  5. The information about the state of a qubit gained by a weakly coupled detector

    Energy Technology Data Exchange (ETDEWEB)

    Ashhab, S; You, J Q; Nori, Franco [Advanced Science Institute, Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama 351-0198 (Japan)], E-mail: ashab@riken.jp

    2009-08-15

    We analyze the information that one can learn about the state of a quantum two-level system, i.e. a qubit, when probed weakly by a nearby detector. In particular, we focus on the case when the qubit Hamiltonian and the qubit's operator being probed by the detector do not commute. Because the qubit's state keeps evolving while being probed and because the measurement data is mixed with detector-related background noise, one might expect the detector to fail in this case. We show, however, that under suitable conditions and by proper analysis of the measurement data useful information about the state of the qubit can be extracted. It turns out that the measurement basis is stochastically determined every time the experiment is repeated. We analyze in detail the probability distributions that govern the choice of measurement bases. We also analyze the information acquisition rate and show that it is largely unaffected by the apparent conflict between the measurement and intrinsic qubit dynamics. We discuss the relation between our analysis and the stochastic master equation that describes the evolution of the qubit's state under the influence of measurement and decoherence. In particular, we write down a stochastic equation that encompasses the usual stochastic master equation for the evolution of the qubit's density matrix and additionally contains the measurement information that can be extracted from the observed signal.

  6. The Future of Information Services in K-12 Schools in Washington State: A Future Search Conference.

    Science.gov (United States)

    Baldwin, Margaret

    1995-01-01

    Discusses the process of future search conferences and describes one held to consider the future of school library media centers and information services in the state of Washington. Highlights include participation by students, librarians, teachers, administrators, and others; strategic and participatory planning; and change processes. (LRW)

  7. Information Literacy in Postsecondary Education in the United Kingdom, the United States, Australia, and New Zealand

    Science.gov (United States)

    Folk, Amanda L.

    2016-01-01

    This comparison seeks to determine if the three documents addressing information literacy skills and competence developed by professional library associations for postsecondary education in four predominantly English-speaking countries--the United Kingdom, the United States, Australia, and New Zealand--have similar or varying conceptions of…

  8. 75 FR 5849 - Financial Management Service; Proposed Collection of Information: Claim Against the United States...

    Science.gov (United States)

    2010-02-04

    ... Fiscal Service Financial Management Service; Proposed Collection of Information: Claim Against the United States for the Proceeds of a Government Check AGENCY: Financial Management Service, Fiscal Service, Treasury. ACTION: Notice and Request for comments. SUMMARY: The Financial Management Service, as part...

  9. 78 FR 22251 - Agency Information Collection Activities; Comment Request; IDEA Part B State Performance Plan...

    Science.gov (United States)

    2013-04-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF EDUCATION Agency Information Collection Activities; Comment Request; IDEA Part B State Performance Plan (SPP) and... in response to this notice will be considered public records. Title of Collection: IDEA Part B...

  10. 78 FR 22253 - Agency Information Collection Activities; Comment Request; IDEA Part C State Performance Plan...

    Science.gov (United States)

    2013-04-15

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF EDUCATION Agency Information Collection Activities; Comment Request; IDEA Part C State Performance Plan (SPP) and... in response to this notice will be considered public records. Title of Collection: IDEA Part C...

  11. Academic Staff Utilization of Information and Communication Technology and Knowledge Creation in Cross River State Universities

    Science.gov (United States)

    Ekpoh, Uduak Imo; Etor, Comfort Robert

    2012-01-01

    This study examined academic staff utilization of Information and Communication Technology (ICT) in knowledge creation in universities in Cross River State. The study was guided by two research questions and one hypothesis. A questionnaire was developed, validated and used for data collection from a sample of 300 academic staff. Descriptive…

  12. Information as Power: An Anthology of Selected United States Army War College Student Papers. Volume 6

    Science.gov (United States)

    2012-05-01

    Groh, Benjamin C. Leitzel, Lawrence E. Strobel, and Mark A. Van Dyke Information as Power is a refereed anthology of United States Army War College...is now the capitol of Serbia. 39. EL Quarantelli, “The Disaster Research Center ( DRC ) Field Studies of Organized Behavior in the Crisis Time Period of

  13. 75 FR 51609 - Classified National Security Information Program for State, Local, Tribal, and Private Sector...

    Science.gov (United States)

    2010-08-23

    ... security information shared by the Federal Government with State, local, tribal, and private sector (SLTPS... entity'' as defined in section 2 of the Homeland Security Act of 2002 (6 U.S.C. 101(11)). (g) ``Private... President [[Page 51609

  14. 42 CFR 495.332 - State Medicaid health information technology (HIT) plan requirements.

    Science.gov (United States)

    2010-10-01

    ..., individuals in long-term care settings and the aged, blind, and disabled. This description must address the... 42 Public Health 5 2010-10-01 2010-10-01 false State Medicaid health information technology (HIT... HEALTH RECORD TECHNOLOGY INCENTIVE PROGRAM Requirements Specific to the Medicaid Program § 495.332...

  15. Robust Transceiver Design for Multiuser MIMO Downlink with Channel Uncertainties

    Science.gov (United States)

    Miao, Wei; Li, Yunzhou; Chen, Xiang; Zhou, Shidong; Wang, Jing

    This letter addresses the problem of robust transceiver design for the multiuser multiple-input-multiple-output (MIMO) downlink where the channel state information at the base station (BS) is imperfect. A stochastic approach which minimizes the expectation of the total mean square error (MSE) of the downlink conditioned on the channel estimates under a total transmit power constraint is adopted. The iterative algorithm reported in [2] is improved to handle the proposed robust optimization problem. Simulation results show that our proposed robust scheme effectively reduces the performance loss due to channel uncertainties and outperforms existing methods, especially when the channel errors of the users are different.

  16. Covert channel capacity analysis based on information entropy%基于信息熵的隐通道能力分析

    Institute of Scientific and Technical Information of China (English)

    陈立; 鞠时光; 周从华; 房芳; 张翼

    2009-01-01

    This paper presented a method based on information entropy to analyze the capacity of covert channels. Built upon noninterference, the method was firstly used to calculate the covert channel capacity, then to analyze the factors that had an impact on this quantity. Finally gave an example of the capacity calculation for covert channels in a multilevel secure database.%给出了一种基于信息熵的隐通道能力分析方法.该方法首先利用无干扰分析法分析隐通道,得到系统状态转换分布特性,然后引入信息熵,进而推导出隐通道能力表达公式.该方法能较好地对隐通道能力进行定量分析,不仅可以对隐通道能力的大小进行计算,还可以分析隐通道能力的影响因素.最后,给出了存在于多级安全数据库中的一种隐通道,并用该方法分析计算了该隐通道的能力.

  17. Secure quantum communication using classical correlated channel

    Science.gov (United States)

    Costa, D.; de Almeida, N. G.; Villas-Boas, C. J.

    2016-10-01

    We propose a secure protocol to send quantum information from one part to another without a quantum channel. In our protocol, which resembles quantum teleportation, a sender (Alice) and a receiver (Bob) share classical correlated states instead of EPR ones, with Alice performing measurements in two different bases and then communicating her results to Bob through a classical channel. Our secure quantum communication protocol requires the same amount of classical bits as the standard quantum teleportation protocol. In our scheme, as in the usual quantum teleportation protocol, once the classical channel is established in a secure way, a spy (Eve) will never be able to recover the information of the unknown quantum state, even if she is aware of Alice's measurement results. Security, advantages, and limitations of our protocol are discussed and compared with the standard quantum teleportation protocol.

  18. Heisenberg-limited metrology with a squeezed vacuum state, three-mode mixing and information recycling

    CERN Document Server

    Tonekaboni, Behnam; Szigeti, Stuart S

    2015-01-01

    We have previously shown that quantum-enhanced atom interferometry can be achieved by mapping the quantum state of squeezed optical vacuum to one of the atomic inputs via a beamsplitter-like process [Phys.~Rev.~A \\textbf{90}, 063630 (2014)]. Here we ask the question: is a better phase sensitivity possible if the quantum state transfer (QST) is described by a three-mode-mixing model, rather than a beamsplitter? The answer is yes, but only if the portion of the optical state not transferred to the atoms is incorporated via information recycling. Surprisingly, our scheme gives a better sensitivity for lower QST efficiencies, and with a sufficiently large degree of squeezing can attain near-Heisenberg-limited sensitivities for arbitrarily small QST efficiencies. Furthermore, we use the quantum Fisher information to demonstrate the near-optimality of our scheme.

  19. A Summary of State Chapter 1 Migrant Education Program Participation and Achievement Information for 1985-86. Volume 2: Achievement.

    Science.gov (United States)

    Gutmann, Babette; And Others

    This report summarizes the achievement information provided by state educational agencies for the Migrant Education Program, 1985-86. Of the 34 states submitting achievement information for the regular term, 29 used norm-referenced tests, 10 used criterion-referenced tests, and 3 used locally developed instruments. Of the 15 states submitting…

  20. The effect of coupled mass transport and internal reforming on modeling of solid oxide fuel cells part I: Channel-level model development and steady-state comparison

    Science.gov (United States)

    Albrecht, Kevin J.; Braun, Robert J.

    2016-02-01

    Dynamic modeling and analysis of solid oxide fuel cell systems can provide insight towards meeting transient response application requirements and enabling an expansion of the operating envelope of these high temperature systems. SOFC modeling for system studies are accomplished with channel-level interface charge transfer models, which implement dynamic conservation equations coupled with additional submodels to capture the porous media mass transport and electrochemistry of the cell. Many of these models may contain simplifications in order to decouple the mass transport, fuel reforming, and electrochemical processes enabling the use of a 1-D model. The reforming reactions distort concentration profiles of the species within the anode, where hydrogen concentration at the triple-phase boundary may be higher or lower than that of the channel altering the local Nernst potential and exchange current density. In part one of this paper series, the modeling equations for the 1-D and 'quasi' 2-D models are presented, and verified against button cell electrochemical and channel-level reforming data. Steady-state channel-level modeling results indicate a 'quasi' 2-D SOFC model predicts a more uniform temperature distribution where differences in the peak cell temperature and maximum temperature gradient are experienced. The differences are most prominent for counter-flow cell with high levels of internal reforming. The transient modeling comparison is discussed in part two of this paper series.