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Sample records for voice channel capacity

  1. Quantum capacity of Pauli channels with memory

    International Nuclear Information System (INIS)

    Huang Peng; He Guangqiang; Lu Yuan; Zeng Guihua

    2011-01-01

    The amount of coherent quantum information that can be reliably transmitted down the memory Pauli channels with Markovian correlated noise is investigated. Two methods for evaluating the quantum capacity of the memory Pauli channels are proposed to try to trace the memory effect on the transmissions of quantum information. We show that the evaluation of quantum capacity can be reduced to the calculation of the initial memory state of each successive transmission. Furthermore, we derive quantum capacities of the memory phase flip channel, bit flip channel and bit-phase flip channel. Also, a lower bound of the quantum capacity of the memory depolarizing channel is obtained. An increase of the degree of memory of the channels has a positive effect on the increase of their quantum capacities.

  2. Effective capacity of correlated MISO channels

    KAUST Repository

    Zhong, Caijun

    2011-06-01

    This paper presents an analytical performance investigation of the capacity limits of correlated multiple-input single-output (MISO) channels in the presence of quality-of-service (QoS) requirements. Exact closed-form expression for the effective capacity of correlated MISO channels is derived. In addition, simple expressions are obtained at the asymptotic high and low signal-to-noise ratio (SNR) regimes, which provide insights into the impact of various system parameters on the effective capacity of the system. Also, a complete characterization of the impact of spatial correlation on the effective capacity is provided with the aid of a majorization theory result. The findings suggest that antenna correlation reduce the effective capacity of the channels. Moreover, a stringent QoS requirement causes a significant reduction in the effective capacity but this can be effectively alleviated by increasing the number of antennas. © 2011 IEEE.

  3. Ergodic Capacity for the SIMO Nakagami- Channel

    Directory of Open Access Journals (Sweden)

    Vagenas EfstathiosD

    2009-01-01

    Full Text Available This paper presents closed-form expressions for the ergodic channel capacity of SIMO (single-input and multiple output wireless systems operating in a Nakagami- fading channel. As the performance of SIMO channel is closely related to the diversity combining techniques, we present closed-form expressions for the capacity of maximal ratio combining (MRC, equal gain combining (EGC, selection combining (SC, and switch and stay (SSC diversity systems operating in Nakagami- fading channels. Also, the ergodic capacity of a SIMO system in a Nakagami- fading channel without any diversity technique is derived. The latter scenario is further investigated for a large amount of receive antennas. Finally, numerical results are presented for illustration.

  4. Modified MIMO Cube for Enhanced Channel Capacity

    Directory of Open Access Journals (Sweden)

    Lajos Nagy

    2012-01-01

    Full Text Available This paper deals with the optimization of MIMO antenna elements' position in modified MIMO cube for getting maximal channel capacity in indoor environment. The dependence of the channel capacity on the antenna orientation was analyzed by simulations. We have also examined the effect of the frequency dependence of the antenna system (in case of conjugate matching and nonconjugate matching for the channel capacity. Based on the simulation results in the created and measured antenna system, the antennas were at a right angle to each other. At the two chosen different structures, we measured the antenna parameters and the channel capacity. In this paper, we present the results of the measurements which clearly confirm our simulations. We will point out the differences between the two antenna structures.

  5. Tema con variazioni: quantum channel capacity

    Science.gov (United States)

    Kretschmann, Dennis; Werner, Reinhard F.

    2004-02-01

    Channel capacity describes the size of the nearly ideal channels, which can be obtained from many uses of a given channel, using an optimal error correcting code. In this paper we collect and compare minor and major variations in the mathematically precise statements of this idea which have been put forward in the literature. We show that all the variations considered lead to equivalent capacity definitions. In particular, it makes no difference whether one requires mean or maximal errors to go to zero, and it makes no difference whether errors are required to vanish for any sequence of block sizes compatible with the rate, or only for one infinite sequence.

  6. Capacity Bounds for Parallel Optical Wireless Channels

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    A system consisting of parallel optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. Under perfect channel-state information at the transmitter (CSIT), the bounds have to be optimized with respect to the power allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the KKT conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose low-complexity power allocation algorithms which are nearly optimal. The optimized capacity lower bound nearly coincides with the capacity at high SNR. Without CSIT, our capacity bounds lead to upper and lower bounds on the outage probability. The outage probability bounds meet at high SNR. The system with average and peak intensity constraints is also discussed.

  7. The least channel capacity for chaos synchronization.

    Science.gov (United States)

    Wang, Mogei; Wang, Xingyuan; Liu, Zhenzhen; Zhang, Huaguang

    2011-03-01

    Recently researchers have found that a channel with capacity exceeding the Kolmogorov-Sinai entropy of the drive system (h(KS)) is theoretically necessary and sufficient to sustain the unidirectional synchronization to arbitrarily high precision. In this study, we use symbolic dynamics and the automaton reset sequence to distinguish the information that is required in identifying the current drive word and obtaining the synchronization. Then, we show that the least channel capacity that is sufficient to transmit the distinguished information and attain the synchronization of arbitrarily high precision is h(KS). Numerical simulations provide support for our conclusions.

  8. Effective capacity of correlated MISO channels

    KAUST Repository

    Zhong, Caijun; Ratnarajah, Tharm; Wong, Kaikit; Alouini, Mohamed-Slim

    2011-01-01

    This paper presents an analytical performance investigation of the capacity limits of correlated multiple-input single-output (MISO) channels in the presence of quality-of-service (QoS) requirements. Exact closed-form expression for the effective

  9. Quantum capacity of dephasing channels with memory

    International Nuclear Information System (INIS)

    D'Arrigo, A; Benenti, G; Falci, G

    2007-01-01

    We show that the amount of coherent quantum information that can be reliably transmitted down a dephasing channel with memory is maximized by separable input states. In particular, we model the channel as a Markov chain or a multimode environment of oscillators. While in the first model, the maximization is achieved for the maximally mixed input state, in the latter it is convenient to exploit the presence of a decoherence-protected subspace generated by memory effects. We explicitly compute the quantum channel capacity for the first model while numerical simulations suggest a lower bound for the latter. In both cases memory effects enhance the coherent information. We present results valid for arbitrary input size

  10. Quasi-superactivation for the classical capacity of quantum channels

    Energy Technology Data Exchange (ETDEWEB)

    Gyongyosi, Laszlo, E-mail: gyongyosi@hit.bme.hu [Quantum Technologies Laboratory, Department of Telecommunications, Budapest University of Technology and Economics, 2 Magyar tudosok krt, Budapest, H-1117, Hungary and Information Systems Research Group, Mathematics and Natural Sciences, Hungarian Ac (Hungary); Imre, Sandor [Quantum Technologies Laboratory, Department of Telecommunications, Budapest University of Technology and Economics, 2 Magyar tudosok krt, Budapest, H-1117 (Hungary)

    2014-12-04

    The superactivation effect has its roots in the extreme violation of additivity of the channel capacity and enables to reliably transmit quantum information over zero-capacity quantum channels. In this work we demonstrate a similar effect for the classical capacity of a quantum channel which previously was thought to be impossible.

  11. Quantum and Private Capacities of Low-Noise Channels

    Science.gov (United States)

    Leditzky, Felix; Leung, Debbie; Smith, Graeme

    2018-04-01

    We determine both the quantum and the private capacities of low-noise quantum channels to leading orders in the channel's distance to the perfect channel. It has been an open problem for more than 20 yr to determine the capacities of some of these low-noise channels such as the depolarizing channel. We also show that both capacities are equal to the single-letter coherent information of the channel, again to leading orders. We thus find that, in the low-noise regime, superadditivity and degenerate codes have a negligible benefit for the quantum capacity, and shielding does not improve the private capacity beyond the quantum capacity, in stark contrast to the situation when noisier channels are considered.

  12. Improvement of Metroliner Telephone Channel Capacity and Modeling of Telephone Channel Demands

    Science.gov (United States)

    1972-03-01

    The channel capacity of the present Metroliner telephone system is analyzed and methods are proposed to increase that capacity without increasing the overall bandwidth. To determine the number of channels required, calculations have been carried out ...

  13. Quantum entanglement enhances the capacity of bosonic channels with memory

    International Nuclear Information System (INIS)

    Cerf, Nicolas J.; Clavareau, Julien; Macchiavello, Chiara; Roland, Jeremie

    2005-01-01

    The bosonic quantum channels have recently attracted a growing interest, motivated by the hope that they open a tractable approach to the generally hard problem of evaluating quantum channel capacities. These studies, however, have always been restricted to memoryless channels. Here, it is shown that the classical capacity of a bosonic Gaussian channel with memory can be significantly enhanced if entangled symbols are used instead of product symbols. For example, the capacity of a photonic channel with 70%-correlated thermal noise of one-third the shot noise is enhanced by about 11% when using 3.8-dB entangled light with a modulation variance equal to the shot noise

  14. Trade-off capacities of the quantum Hadamard channels

    International Nuclear Information System (INIS)

    Bradler, Kamil; Hayden, Patrick; Touchette, Dave; Wilde, Mark M.

    2010-01-01

    Coding theorems in quantum Shannon theory express the ultimate rates at which a sender can transmit information over a noisy quantum channel. More often than not, the known formulas expressing these transmission rates are intractable, requiring an optimization over an infinite number of uses of the channel. Researchers have rarely found quantum channels with a tractable classical or quantum capacity, but when such a finding occurs, it demonstrates a complete understanding of that channel's capabilities for transmitting classical or quantum information. Here we show that the three-dimensional capacity region for entanglement-assisted transmission of classical and quantum information is tractable for the Hadamard class of channels. Examples of Hadamard channels include generalized dephasing channels, cloning channels, and the Unruh channel. The generalized dephasing channels and the cloning channels are natural processes that occur in quantum systems through the loss of quantum coherence or stimulated emission, respectively. The Unruh channel is a noisy process that occurs in relativistic quantum information theory as a result of the Unruh effect and bears a strong relationship to the cloning channels. We give exact formulas for the entanglement-assisted classical and quantum communication capacity regions of these channels. The coding strategy for each of these examples is superior to a naieve time-sharing strategy, and we introduce a measure to determine this improvement.

  15. Quantum Capacity under Adversarial Quantum Noise: Arbitrarily Varying Quantum Channels

    Science.gov (United States)

    Ahlswede, Rudolf; Bjelaković, Igor; Boche, Holger; Nötzel, Janis

    2013-01-01

    We investigate entanglement transmission over an unknown channel in the presence of a third party (called the adversary), which is enabled to choose the channel from a given set of memoryless but non-stationary channels without informing the legitimate sender and receiver about the particular choice that he made. This channel model is called an arbitrarily varying quantum channel (AVQC). We derive a quantum version of Ahlswede's dichotomy for classical arbitrarily varying channels. This includes a regularized formula for the common randomness-assisted capacity for entanglement transmission of an AVQC. Quite surprisingly and in contrast to the classical analog of the problem involving the maximal and average error probability, we find that the capacity for entanglement transmission of an AVQC always equals its strong subspace transmission capacity. These results are accompanied by different notions of symmetrizability (zero-capacity conditions) as well as by conditions for an AVQC to have a capacity described by a single-letter formula. In the final part of the paper the capacity of the erasure-AVQC is computed and some light shed on the connection between AVQCs and zero-error capacities. Additionally, we show by entirely elementary and operational arguments motivated by the theory of AVQCs that the quantum, classical, and entanglement-assisted zero-error capacities of quantum channels are generically zero and are discontinuous at every positivity point.

  16. On Capacity of the Writing onto Fast Fading Dirt Channel

    OpenAIRE

    Rini, Stefano; Shamai, Shlomo

    2016-01-01

    The "Writing onto Fast Fading Dirt" (WFFD) channel is investigated to study the effects of partial channel knowledge on the capacity of the "writing on dirty paper" channel. The WFFD channel is the Gel'fand-Pinsker channel in which the output is obtained as the sum of the input, white Gaussian noise and a fading-times-state term. The fading-times-state term is equal to the element-wise product of the channel state sequence, known only at the transmitter, and a fast fading process, known only ...

  17. Wideband MIMO Channel Capacity Analysis in Multiprobe Anechoic Chamber Setups

    DEFF Research Database (Denmark)

    Fan, Wei; Kyosti, Pekka; Nielsen, Jesper Ødum

    2016-01-01

    been used to determine the test area size for a limited number of probes. However, it is desirable that the test area size is defined in terms of data rate deviation of the simulated channel in the laboratory from that of the target channel model. This paper reports MIMO capacity analysis results...... for wideband spatio-temporal channel models, with emphasis on the impact of spatial correlation at the transmit (Tx) side, the channel model, and the spatial correlation at the Rx side on the capacity simulation accuracy. Simulation results show that the number of probes is irrelevant to capacity simulation......This paper discusses over the air (OTA) testing for multiple input multiple output (MIMO) capable terminals with emphasis on wideband MIMO channel capacity analysis in a multi-probe anechoic chamber setup. In the literature, the spatial correlation simulation accuracy at the receiver (Rx) side has...

  18. Effective capacity of multiple antenna channels: Correlation and keyhole

    KAUST Repository

    Zhong, Caijun

    2012-01-01

    In this study, the authors derive the effective capacity limits for multiple antenna channels which quantify the maximum achievable rate with consideration of link-layer delay-bound violation probability. Both correlated multiple-input single-output and multiple-input multiple-output keyhole channels are studied. Based on the closed-form exact expressions for the effective capacity of both channels, the authors look into the asymptotic high and low signal-to-noise ratio regimes, and derive simple expressions to gain more insights. The impact of spatial correlation on effective capacity is also characterised with the aid of a majorisation theory result. It is revealed that antenna correlation reduces the effective capacity of the channels and a stringent quality-of-service requirement causes a severe reduction in the effective capacity but can be alleviated by increasing the number of antennas. © 2012 The Institution of Engineering and Technology.

  19. Capacity of Fading Channels in the Low Power Regime

    KAUST Repository

    Benkhelifa, Fatma

    2013-01-01

    The low power regime has attracted various researchers in the information theory and communication communities to understand the performance limits of wireless systems. Indeed, the energy consumption is becoming one of the major limiting factors in wireless systems. As such, energy-efficient wireless systems are of major importance to the next generation wireless systems designers. The capacity is a metric that measures the performance limit of a wireless system. The study of the ergodic capacity of some fading channels in the low power regime is the main subject of this thesis. In our study, we consider that the receiver has always a full knowledge of the channel state information. However, we assume that the transmitter has possibly imperfect knowledge of the channel state information, i.e. he knows either perfectly the channel or only an estimated version of the channel. Both radio frequency and free space optical communication channel models are considered. The main contribution of this work is the explicit characterization of how the capacity scales as function of the signal-to-noise ratio in the low power regime. This allows us to characterize the gain due to the perfect knowledge compared to no knowledge of the channel state information at the transmitter. In particular, we show that the gain increases logarithmically for radio frequency communication. However, the gain increases as log2(Pavg) or log4(Pavg) for free-space optical communication, where Pavg is the average power constraint imposed to the input. Furthermore, we characterize the capacity of cascaded fading channels and we applied the result to Rayleigh-product fading channel and to a free-space optical link over gamma-gamma atmospheric turbulence in the presence of pointing errors. Finally, we study the capacity of Nakagami-m fading channel under quality of service constraints, namely the effective capacity. We have shown that the effective capacity converges to Shannon capacity in the very low

  20. Secrecy Capacity of a Class of Orthogonal Relay Eavesdropper Channels

    Directory of Open Access Journals (Sweden)

    Aggarwal Vaneet

    2009-01-01

    Full Text Available The secrecy capacity of relay channels with orthogonal components is studied in the presence of an additional passive eavesdropper node. The relay and destination receive signals from the source on two orthogonal channels such that the destination also receives transmissions from the relay on its channel. The eavesdropper can overhear either one or both of the orthogonal channels. Inner and outer bounds on the secrecy capacity are developed for both the discrete memoryless and the Gaussian channel models. For the discrete memoryless case, the secrecy capacity is shown to be achieved by a partial decode-and-forward (PDF scheme when the eavesdropper can overhear only one of the two orthogonal channels. Two new outer bounds are presented for the Gaussian model using recent capacity results for a Gaussian multiantenna point-to-point channel with a multiantenna eavesdropper. The outer bounds are shown to be tight for two subclasses of channels. The first subclass is one in which the source and relay are clustered, and the eavesdropper receives signals only on the channel from the source and the relay to the destination, for which the PDF strategy is optimal. The second is a subclass in which the source does not transmit to the relay, for which a noise-forwarding strategy is optimal.

  1. OPRA capacity bounds for selection diversity over generalized fading channels

    KAUST Repository

    Hanif, Muhammad Fainan

    2014-05-01

    Channel side information at the transmitter can increase the average capacity by enabling optimal power and rate adaptation. The resulting optimal power and rate adaptation (OPRA) capacity rarely has a closed-form analytic expression. In this paper, lower and upper bounds on OPRA capacity for selection diversity scheme are presented. These bounds hold for variety of fading channels including log-normal and generalized Gamma distributed models and have very simple analytic expressions for easy evaluation even for kth best path selection. Some selected numerical results show that the newly proposed bounds closely approximate the actual OPRA capacity. © 2014 IEEE.

  2. OPRA capacity bounds for selection diversity over generalized fading channels

    KAUST Repository

    Hanif, Muhammad Fainan; Yang, Hongchuan; Alouini, Mohamed-Slim

    2014-01-01

    , lower and upper bounds on OPRA capacity for selection diversity scheme are presented. These bounds hold for variety of fading channels including log-normal and generalized Gamma distributed models and have very simple analytic expressions for easy

  3. On the Secrecy Capacity of MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine; Rezki, Zouheir; Ghrayeb, Ali; Alouini, Mohamed-Slim

    2017-01-01

    We study the secrecy capacity of the multiple- input single-output (MISO) Gaussian wiretap visible light communication (VLC) channel. We study a typical VLC scenario with one transmitter, one legitimate receiver, and one eavesdropper. Specifically

  4. Effective capacity of multiple antenna channels: Correlation and keyhole

    KAUST Repository

    Zhong, Caijun; Ratnarajah, Tharm; Wong, Kaikit; Alouini, Mohamed-Slim

    2012-01-01

    In this study, the authors derive the effective capacity limits for multiple antenna channels which quantify the maximum achievable rate with consideration of link-layer delay-bound violation probability. Both correlated multiple-input single

  5. Relationship Between Capacity and Pathloss for Indoor MIMO Channels

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Andersen, Jørgen Bach; Bauch, Gerhard

    2006-01-01

    MIMO transmission systems exploit scattering in the radio channel to achieve high capacity for a given SNR. A high pathloss is generally expected for channels with rich scattering, suggesting that a high SNR and rich multipath are competing goals. The current work investigates this issue based on...

  6. MIMO Channel Capacity for Handsets in Data Mode Operation

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Yanakiev, Boyan; Bonev, Ivan Bonev

    2010-01-01

    The current paper concerns realistic evaluation of the capacity of the MIMO channel between a BS and handheld device, such as a PDA or smart phone, held in front of the user’s body (data mode). The work is based on measurements of the MIMO channel between two widely separated BSs in a micro...

  7. On the Capacity of the Dirty Paper Channel with Fast Fading and Discrete Channel States

    OpenAIRE

    Rini, Stefano; Shitz, Shlomo Shamai

    2016-01-01

    The "writing dirty paper" capacity result crucially dependents on the perfect channel knowledge at the transmitter as the presence of even a small uncertainty in the channel realization gravely hampers the ability of the transmitter to pre-code its transmission against the channel state. This is particularly disappointing as it implies that interference pre-coding in practical systems is effective only when the channel estimates at the users have very high precision, a condition which is gene...

  8. Low-SNR Capacity of MIMO Optical Intensity Channels

    KAUST Repository

    Chaaban, Anas

    2017-09-18

    The capacity of the multiple-input multiple-output (MIMO) optical intensity channel is studied, under both average and peak intensity constraints. We focus on low SNR, which can be modeled as the scenario where both constraints proportionally vanish, or where the peak constraint is held constant while the average constraint vanishes. A capacity upper bound is derived, and is shown to be tight at low SNR under both scenarios. The capacity achieving input distribution at low SNR is shown to be a maximally-correlated vector-binary input distribution. Consequently, the low-SNR capacity of the channel is characterized. As a byproduct, it is shown that for a channel with peak intensity constraints only, or with peak intensity constraints and individual (per aperture) average intensity constraints, a simple scheme composed of coded on-off keying, spatial repetition, and maximum-ratio combining is optimal at low SNR.

  9. Low-SNR Capacity of MIMO Optical Intensity Channels

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2017-01-01

    The capacity of the multiple-input multiple-output (MIMO) optical intensity channel is studied, under both average and peak intensity constraints. We focus on low SNR, which can be modeled as the scenario where both constraints proportionally vanish, or where the peak constraint is held constant while the average constraint vanishes. A capacity upper bound is derived, and is shown to be tight at low SNR under both scenarios. The capacity achieving input distribution at low SNR is shown to be a maximally-correlated vector-binary input distribution. Consequently, the low-SNR capacity of the channel is characterized. As a byproduct, it is shown that for a channel with peak intensity constraints only, or with peak intensity constraints and individual (per aperture) average intensity constraints, a simple scheme composed of coded on-off keying, spatial repetition, and maximum-ratio combining is optimal at low SNR.

  10. 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.

  11. On the secrecy capacity of the wiretap channel with imperfect main channel estimation

    KAUST Repository

    Rezki, Zouheir

    2014-10-01

    We study the secrecy capacity of fast fading channels under imperfect main channel (between the transmitter and the legitimate receiver) estimation at the transmitter. Lower and upper bounds on the ergodic secrecy capacity are derived for a class of independent identically distributed (i.i.d.) fading channels. The achievable rate follows from a standard wiretap code in which a simple on-off power control is employed along with a Gaussian input. The upper bound is obtained using an appropriate correlation scheme of the main and eavesdropper channels and is the best known upper bound so far. The upper and lower bounds coincide with recently derived ones in case of perfect main CSI. Furthermore, the upper bound is tight in case of no main CSI, where the secrecy capacity is equal to zero. Asymptotic analysis at high and low signal-to-noise ratio (SNR) is also given. At high SNR, we show that the capacity is bounded by providing upper and lower bounds that depend on the channel estimation error. At low SNR, however, we prove that the secrecy capacity is asymptotically equal to the capacity of the main channel as if there were no secrecy constraint. Numerical results are provided for i.i.d. Rayleigh fading channels.

  12. Capacity bounds for parallel IM-DD optical wireless channels

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    A system consisting of parallel intensity-modulation direct-detection optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. If channel-state information is available at the transmitter, the bounds have to be optimized with respect to intensity allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the Karush-Kuhn-Tucker conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose a low-complexity intensity allocation algorithm which is nearly optimal. The optimized capacity lower bound coincides with the capacity at high signal-to-noise ratio. © 2016 IEEE.

  13. Capacity bounds for parallel IM-DD optical wireless channels

    KAUST Repository

    Chaaban, Anas

    2016-07-26

    A system consisting of parallel intensity-modulation direct-detection optical wireless channels with a total average intensity constraint is studied. Capacity upper and lower bounds for this system are derived. If channel-state information is available at the transmitter, the bounds have to be optimized with respect to intensity allocation over the parallel channels. The optimization of the lower bound is non-convex, however, the Karush-Kuhn-Tucker conditions can be used to find a list of possible solutions one of which is optimal. The optimal solution can then be found by an exhaustive search algorithm, which is computationally expensive. To overcome this, we propose a low-complexity intensity allocation algorithm which is nearly optimal. The optimized capacity lower bound coincides with the capacity at high signal-to-noise ratio. © 2016 IEEE.

  14. Transitions in the Communication Capacity of Dissipative Qubit Channels

    Science.gov (United States)

    Daems, D.

    2009-05-01

    The information transmission is studied for quantum channels in which the noise includes dissipative effects, more specifically, nonunitality. Noise is usually a nuisance but can sometimes be helpful. For these channels, the communication capacity is shown to increase with the dissipative component of the noise and may exhibit transitions beyond which it increases faster. The optimal states are constructed analytically as well as the pertaining “phase” diagram.

  15. Polaractivation for classical zero-error capacity of qudit channels

    Energy Technology Data Exchange (ETDEWEB)

    Gyongyosi, Laszlo, E-mail: gyongyosi@hit.bme.hu [Quantum Technologies Laboratory, Department of Telecommunications, Budapest University of Technology and Economics, 2 Magyar tudosok krt, Budapest, H-1117, Hungary and Information Systems Research Group, Mathematics and Natural Sciences, Hungarian Ac (Hungary); Imre, Sandor [Quantum Technologies Laboratory, Department of Telecommunications, Budapest University of Technology and Economics, 2 Magyar tudosok krt, Budapest, H-1117 (Hungary)

    2014-12-04

    We introduce a new phenomenon for zero-error transmission of classical information over quantum channels that initially were not able for zero-error classical communication. The effect is called polaractivation, and the result is similar to the superactivation effect. We use the Choi-Jamiolkowski isomorphism and the Schmidt-theorem to prove the polaractivation of classical zero-error capacity and define the polaractivator channel coding scheme.

  16. Asymmetric information capacities of reciprocal pairs of quantum channels

    Science.gov (United States)

    Rosati, Matteo; Giovannetti, Vittorio

    2018-05-01

    Reciprocal pairs of quantum channels are defined as completely positive transformations which admit a rigid, distance-preserving, yet not completely positive transformation that allows one to reproduce the outcome of one from the corresponding outcome of the other. From a classical perspective these transmission lines should exhibit the same communication efficiency. This is no longer the case in the quantum setting: explicit asymmetric behaviors are reported studying the classical communication capacities of reciprocal pairs of depolarizing and Weyl-covariant channels.

  17. Capacity Bounds and High-SNR Capacity of MIMO Intensity-Modulation Optical Channels

    KAUST Repository

    Chaaban, Anas

    2018-02-19

    The capacity of the intensity modulation direct detection multiple-input multiple-output channel is studied. Therein, the nonnegativity constraint of the transmit signal limits the applicability of classical schemes, including precoding. Thus, new ways are required for deriving capacity bounds for this channel. To this end, capacity lower bounds are developed in this paper by deriving the achievable rates of two precodingfree schemes: Channel inversion and QR decomposition. The achievable rate of a DC-offset SVD-based scheme is also derived as a benchmark. Then, capacity upper bounds are derived and compared against the lower bounds. As a result, the capacity at high signal-to-noise ratio (SNR) is characterized for the case where the number of transmit apertures is not larger than the number of receive apertures, and is shown to be achievable by the QR decomposition scheme. This is shown for a channel with average intensity or peak intensity constraints. Under both constraints, the high-SNR capacity is approximated within a small gap. Extensions to a channel with more transmit apertures than receive apertures are discussed, and capacity bounds for this case are derived.

  18. Capacity Bounds and High-SNR Capacity of MIMO Intensity-Modulation Optical Channels

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2018-01-01

    The capacity of the intensity modulation direct detection multiple-input multiple-output channel is studied. Therein, the nonnegativity constraint of the transmit signal limits the applicability of classical schemes, including precoding. Thus, new ways are required for deriving capacity bounds for this channel. To this end, capacity lower bounds are developed in this paper by deriving the achievable rates of two precodingfree schemes: Channel inversion and QR decomposition. The achievable rate of a DC-offset SVD-based scheme is also derived as a benchmark. Then, capacity upper bounds are derived and compared against the lower bounds. As a result, the capacity at high signal-to-noise ratio (SNR) is characterized for the case where the number of transmit apertures is not larger than the number of receive apertures, and is shown to be achievable by the QR decomposition scheme. This is shown for a channel with average intensity or peak intensity constraints. Under both constraints, the high-SNR capacity is approximated within a small gap. Extensions to a channel with more transmit apertures than receive apertures are discussed, and capacity bounds for this case are derived.

  19. Channel capacities versus entanglement measures in multiparty quantum states

    International Nuclear Information System (INIS)

    Sen, Aditi; Sen, Ujjwal

    2010-01-01

    For quantum states of two subsystems, highly entangled states have a higher capacity of transmitting classical as well as quantum information, and vice versa. We show that this is no more the case in general: Quantum capacities of multiaccess channels, motivated by communication in quantum networks, do not have any relation with genuine multiparty entanglement measures. Importantly, the statement is demonstrated for arbitrary multipartite entanglement measures. Along with revealing the structural richness of multiaccess channels, this gives us a tool to classify multiparty quantum states from the perspective of its usefulness in quantum networks, which cannot be visualized by any genuine multiparty entanglement measure.

  20. MIMO channel capacity with full CSI at Low SNR

    KAUST Repository

    Tall, Abdoulaye

    2012-10-01

    In this paper, we characterize the ergodic capacity of Multiple Input Multiple Output (MIMO) Rayleigh fading channels with full channel state information (CSI) at both the transmitter (CSI-T) and the receiver (CSI-R) at asymptotically low signal-to-noise ratio (SNR). A simple analytical expression of the capacity is derived for any number of transmit and receive antennas. This characterization clearly shows the substantial gain in terms of capacity over the no CSI-T case and gives a good insight on the effect of the number of antennas used. In addition, an On-Off transmission scheme is proposed and is shown to be asymptotically capacity-achieving. © 2012 IEEE.

  1. On the ergodic secrecy capacity of the wiretap channel under imperfect main channel estimation

    KAUST Repository

    Rezki, Zouheir; Khisti, Ashish J.; Alouini, Mohamed-Slim

    2011-01-01

    imperfect main channel estimation at the transmitter. Inner and outer bounds on the ergodic secrecy capacity are derived for a class of independent identically distributed (i.i.d.) fading channels. The achievable rate is a simple on-off scheme using a

  2. 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.

  3. On the secrecy capacity of the MISO wiretap channel under imperfect channel estimation

    KAUST Repository

    Rezki, Zouheir; Alomair, Basel; Alouini, Mohamed-Slim

    2014-01-01

    We consider a wiretap channel consisting of a source with multiple antennas, a legitimate receiver and an eavesdropper with a single antenna each. The channels between the source and the receivers undergo fast fading. We assume that the transmitter, in addition to the statistics of both channels, is only aware of a noisy version of the CSI to the legitimate receiver referred to as main channel. The legitimate receiver is aware of both its instantaneous channel gain and the transmitter's estimate of the main channel. On the other hand, the eavesdropper's receiver, in addition to its instantaneous channel realization, is aware of the actual main CSI and the transmitter's estimate as well. While the capacity of this channel is still open even with perfect CSI at the transmitter, we provide in this paper upper and lower bounds on the secrecy capacity. The upper bound is tighter than the one corresponding to perfect main CSI and the gap between the two upper bounds is characterized in function of the channel estimation error variance, at high-SNR. Furthermore, we show that our upper and lower bounds coincide in the case of no main CSI providing a trivial secrecy capacity.

  4. On the secrecy capacity of the MISO wiretap channel under imperfect channel estimation

    KAUST Repository

    Rezki, Zouheir

    2014-12-01

    We consider a wiretap channel consisting of a source with multiple antennas, a legitimate receiver and an eavesdropper with a single antenna each. The channels between the source and the receivers undergo fast fading. We assume that the transmitter, in addition to the statistics of both channels, is only aware of a noisy version of the CSI to the legitimate receiver referred to as main channel. The legitimate receiver is aware of both its instantaneous channel gain and the transmitter\\'s estimate of the main channel. On the other hand, the eavesdropper\\'s receiver, in addition to its instantaneous channel realization, is aware of the actual main CSI and the transmitter\\'s estimate as well. While the capacity of this channel is still open even with perfect CSI at the transmitter, we provide in this paper upper and lower bounds on the secrecy capacity. The upper bound is tighter than the one corresponding to perfect main CSI and the gap between the two upper bounds is characterized in function of the channel estimation error variance, at high-SNR. Furthermore, we show that our upper and lower bounds coincide in the case of no main CSI providing a trivial secrecy capacity.

  5. On the ergodic secrecy capacity of the wiretap channel under imperfect main channel estimation

    KAUST Repository

    Rezki, Zouheir

    2011-11-01

    The ergodic secrecy capacity of the wiretap channel is known when the main channel (between the transmitter and the legitimate receiver) state information (CSI) is perfect at the transmitter and the coherence period is sufficiently large to enable random coding arguments in each block. In a fast fading scenario, when the codeword length spans many coherence periods, the secrecy capacity is still not known. In this paper, we present a framework that characterizes this secrecy capacity under imperfect main channel estimation at the transmitter. Inner and outer bounds on the ergodic secrecy capacity are derived for a class of independent identically distributed (i.i.d.) fading channels. The achievable rate is a simple on-off scheme using a Gaussian input. The upper bound is obtained using an appropriate correlation scheme of the main and the eavesdropper channels. The upper and the lower bounds coincide with recently derived ones in the perfect main CSI extreme. Furthermore, the lower bound matches the upper bound in no main CSI extreme, where the secrecy capacity is equal to zero. Numerical results are provided for independent identically distributed (i.i.d.) Rayleigh fading channels. © 2011 IEEE.

  6. 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.

  7. 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.

  8. Secrecy Capacity Analysis over α−μ Fading Channels

    KAUST Repository

    Lei, Hongjiang

    2017-02-15

    In this work, we study the secrecy capacity of the classic Wyner’s model over the α − μ fading channels, where α and μ specify the nonlinearity and clustering of fading channels, respectively. The average secrecy capacity (ASC) is derived in closed-form by using the extended generalized bivariate Fox’s Hfunction (EGBFHF). Moreover, the asymptotic analysis of ASC in high signal-to-noise ratio (SNR) regime is conducted. The asymptotic results unveil that the ASC follows the scaling law of Θ(ln p), where p stands for the ratio between the average powers of main channels and eavesdropping channels. Moreover, the ASC can be enhanced by increasing the transmit SNR, while there exists a ceiling of ASC as the SNRs at both sides are improved simultaneously. The accuracy of the analytical results is validated by Monte-Carlo simulations. The numerical results show that rigorous fading channels are beneficial to the secrecy performance, that is, serious nonlinearity (small α) and sparse clustering (small μ) will lead to the improvement of ASC.

  9. Secrecy Capacity Analysis over α−μ Fading Channels

    KAUST Repository

    Lei, Hongjiang; Ansari, Imran Shafique; Pan, Gaofeng; Alomair, Basel; Alouini, Mohamed-Slim

    2017-01-01

    In this work, we study the secrecy capacity of the classic Wyner’s model over the α − μ fading channels, where α and μ specify the nonlinearity and clustering of fading channels, respectively. The average secrecy capacity (ASC) is derived in closed-form by using the extended generalized bivariate Fox’s Hfunction (EGBFHF). Moreover, the asymptotic analysis of ASC in high signal-to-noise ratio (SNR) regime is conducted. The asymptotic results unveil that the ASC follows the scaling law of Θ(ln p), where p stands for the ratio between the average powers of main channels and eavesdropping channels. Moreover, the ASC can be enhanced by increasing the transmit SNR, while there exists a ceiling of ASC as the SNRs at both sides are improved simultaneously. The accuracy of the analytical results is validated by Monte-Carlo simulations. The numerical results show that rigorous fading channels are beneficial to the secrecy performance, that is, serious nonlinearity (small α) and sparse clustering (small μ) will lead to the improvement of ASC.

  10. RFID Ownership Transfer with Positive Secrecy Capacity Channels

    Directory of Open Access Journals (Sweden)

    Jorge Munilla

    2016-12-01

    Full Text Available RFID ownership transfer protocols (OTPs transfer tag ownership rights. Recently, there has been considerable interest in such protocols; however, guaranteeing privacy for symmetric-key settings without trusted third parties (TTPs is a challenge still unresolved. In this paper, we address this issue and show that it can be solved by using channels with positive secrecy capacity. We implement these channels with noisy tags and provide practical values, thus proving that perfect secrecy is theoretically possible. We then define a communication model that captures spatiotemporal events and describe a first example of symmetric-key based OTP that: (i is formally secure in the proposed communication model and (ii achieves privacy with a noisy tag wiretap channel without TTPs.

  11. A new simple model for composite fading channels: Second order statistics and channel capacity

    KAUST Repository

    Yilmaz, Ferkan

    2010-09-01

    In this paper, we introduce the most general composite fading distribution to model the envelope and the power of the received signal in such fading channels as millimeter wave (60 GHz or above) fading channels and free-space optical channels, which we term extended generalized-K (EGK) composite fading distribution. We obtain the second-order statistics of the received signal envelope characterized by the EGK composite fading distribution. Expressions for probability density function, cumulative distribution function, level crossing rate and average fade duration, moments, amount of fading and average capacity are derived. Numerical and computer simulation examples validate the accuracy of the presented mathematical analysis. © 2010 IEEE.

  12. 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.

  13. Novel asymptotic results on the high-order statistics of the channel capacity over generalized fading channels

    KAUST Repository

    Yilmaz, Ferkan; Alouini, Mohamed-Slim

    2012-01-01

    The exact analysis of the higher-order statistics of the channel capacity (i.e., higher-order ergodic capacity) often leads to complicated expressions involving advanced special functions. In this paper, we provide a generic framework

  14. Quantum-capacity-approaching codes for the detected-jump channel

    International Nuclear Information System (INIS)

    Grassl, Markus; Wei Zhaohui; Ji Zhengfeng; Zeng Bei

    2010-01-01

    The quantum-channel capacity gives the ultimate limit for the rate at which quantum data can be reliably transmitted through a noisy quantum channel. Degradable quantum channels are among the few channels whose quantum capacities are known. Given the quantum capacity of a degradable channel, it remains challenging to find a practical coding scheme which approaches capacity. Here we discuss code designs for the detected-jump channel, a degradable channel with practical relevance describing the physics of spontaneous decay of atoms with detected photon emission. We show that this channel can be used to simulate a binary classical channel with both erasures and bit flips. The capacity of the simulated classical channel gives a lower bound on the quantum capacity of the detected-jump channel. When the jump probability is small, it almost equals the quantum capacity. Hence using a classical capacity-approaching code for the simulated classical channel yields a quantum code which approaches the quantum capacity of the detected-jump channel.

  15. 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.

  16. MIMO Intensity-Modulation Channels: Capacity Bounds and High SNR Characterization

    KAUST Repository

    Chaaban, Anas

    2016-10-01

    The capacity of MIMO intensity modulation channels is studied. The nonnegativity of the transmit signal (intensity) poses a challenge on the precoding of the transmit signal, which limits the applicability of classical schemes in this type of channels. To resolve this issue, capacity lower bounds are developed by using precoding-free schemes. This is achieved by channel inversion or QR decomposition to convert the MIMO channel to a set of parallel channels. The achievable rate of a DC-offset SVD based scheme is also derived as a benchmark. Then, a capacity upper bound is derived and is shown to coincide with the achievable rate of the QR decomposition based scheme at high SNR, consequently characterizing the high-SNR capacity of the channel. The high-SNR gap between capacity and the achievable rates of the channel inversion and the DC-offset SVD based schemes is also characterized. Finally, the ergodic capacity of the channel is also briefly discussed.

  17. Capacity and optimal collusion attack channels for Gaussian fingerprinting games

    Science.gov (United States)

    Wang, Ying; Moulin, Pierre

    2007-02-01

    constraints. Under those constraints on the fingerprint embedder and the colluders, fingerprinting capacity is obtained as the solution of a mutual-information game involving probability density functions (pdf's) designed by the embedder and the colluders. We show that the optimal fingerprinting strategy is a Gaussian test channel where the fingerprinted signal is the sum of an attenuated version of the cover signal plus a Gaussian information-bearing noise, and the optimal collusion strategy is to average fingerprinted signals possessed by all the colluders and pass the averaged copy through a Gaussian test channel. The capacity result and the optimal strategies are the same for both the private and public games. In the former scenario, the original covertext is available to the decoder, while in the latter setup, the original covertext is available to the encoder but not to the decoder.

  18. 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.

  19. Capacity Bounds and Mapping Design for Binary Symmetric Relay Channels

    Directory of Open Access Journals (Sweden)

    Majid Nasiri Khormuji

    2012-12-01

    Full Text Available Capacity bounds for a three-node binary symmetric relay channel with orthogonal components at the destination are studied. The cut-set upper bound and the rates achievable using decode-and-forward (DF, partial DF and compress-and-forward (CF relaying are first evaluated. Then relaying strategies with finite memory-length are considered. An efficient algorithm for optimizing the relay functions is presented. The Boolean Fourier transform is then employed to unveil the structure of the optimized mappings. Interestingly, the optimized relay functions exhibit a simple structure. Numerical results illustrate that the rates achieved using the optimized low-dimensional functions are either comparable to those achieved by CF or superior to those achieved by DF relaying. In particular, the optimized low-dimensional relaying scheme can improve on DF relaying when the quality of the source-relay link is worse than or comparable to that of other links.

  20. Capacity of a quantum memory channel correlated by matrix product states

    Science.gov (United States)

    Mulherkar, Jaideep; Sunitha, V.

    2018-04-01

    We study the capacity of a quantum channel where channel acts like controlled phase gate with the control being provided by a one-dimensional quantum spin chain environment. Due to the correlations in the spin chain, we get a quantum channel with memory. We derive formulas for the quantum capacity of this channel when the spin state is a matrix product state. Particularly, we derive exact formulas for the capacity of the quantum memory channel when the environment state is the ground state of the AKLT model and the Majumdar-Ghosh model. We find that the behavior of the capacity for the range of the parameters is analytic.

  1. Solving for the capacity of a noisy lossy bosonic channel via the master equation

    International Nuclear Information System (INIS)

    Qin Tao; Zhao Meisheng; Zhang Yongde

    2006-01-01

    We discuss the noisy lossy bosonic channel by exploiting master equations. The capacity of the noisy lossy bosonic channel and the criterion for the optimal capacities are derived. Consequently, we verify that master equations can be a tool to study bosonic channels

  2. 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.

  3. On the Secrecy Capacity of MISO Visible Light Communication Channels

    KAUST Repository

    Arfaoui, Mohamed Amine

    2017-02-07

    We study the secrecy capacity of the multiple- input single-output (MISO) Gaussian wiretap visible light communication (VLC) channel. We study a typical VLC scenario with one transmitter, one legitimate receiver, and one eavesdropper. Specifically, we compute the achievable secrecy rate for various input signaling distributions, including the truncated generalized normal (TGN) and uniform distributions. The transmitter is equipped with multiple light sources, while the legitimate and unauthorized receivers are each equipped with a single photodetector. We analyze the achievable secrecy rates via transmit beamforming and artificial noise. In addition, both zero-forcing beamforming and robust beamforming are considered. In the former case, the location of the eavesdropper is assumed to be known, whereas in the latter case, the location of the eavesdropper is unknown. Our numerical results show that the secrecy rate achieved by the TGN distribution is significantly improved as compared to those achieved by the truncated Gaussian and uniform distributions, for both zero-forcing beamforming and robust beamforming. We also derive an upper bound on the achievable secrecy capacity that we used to assess the closeness of the achievable secrecy rates to the derived bound.

  4. Quantum capacity under adversarial quantum noise: arbitrarily varying quantum channels

    OpenAIRE

    Ahlswede, Rudolf; Bjelakovic, Igor; Boche, Holger; Noetzel, Janis

    2010-01-01

    We investigate entanglement transmission over an unknown channel in the presence of a third party (called the adversary), which is enabled to choose the channel from a given set of memoryless but non-stationary channels without informing the legitimate sender and receiver about the particular choice that he made. This channel model is called arbitrarily varying quantum channel (AVQC). We derive a quantum version of Ahlswede's dichotomy for classical arbitrarily varying channels. This includes...

  5. Higher order capacity statistics of multi-hop transmission systems over Rayleigh fading channels

    KAUST Repository

    Yilmaz, Ferkan; Tabassum, Hina; Alouini, Mohamed-Slim

    2012-01-01

    In this paper, we present an exact analytical expression to evaluate the higher order statistics of the channel capacity for amplify and forward (AF) multihop transmission systems operating over Rayleigh fading channels. Furthermore, we present

  6. 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.

  7. Sounds like a winner: voice pitch influences perception of leadership capacity in both men and women.

    Science.gov (United States)

    Klofstad, Casey A; Anderson, Rindy C; Peters, Susan

    2012-07-07

    It is well known that non-human animals respond to information encoded in vocal signals, and the same can be said of humans. Specifically, human voice pitch affects how speakers are perceived. As such, does voice pitch affect how we perceive and select our leaders? To answer this question, we recorded men and women saying 'I urge you to vote for me this November'. Each recording was manipulated digitally to yield a higher- and lower-pitched version of the original. We then asked men and women to vote for either the lower- or higher-pitched version of each voice. Our results show that both men and women select male and female leaders with lower voices. These findings suggest that men and women with lower-pitched voices may be more successful in obtaining positions of leadership. This might also suggest that because women, on average, have higher-pitched voices than men, voice pitch could be a factor that contributes to fewer women holding leadership roles than men. Additionally, while people are free to choose their leaders, these results clearly demonstrate that these choices cannot be understood in isolation from biological influences.

  8. Channel Capacity Calculation at Large SNR and Small Dispersion within Path-Integral Approach

    Science.gov (United States)

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

    2018-04-01

    We consider the optical fiber channel modelled by the nonlinear Shrödinger equation with additive white Gaussian noise. Using Feynman path-integral approach for the model with small dispersion we find the first nonzero corrections to the conditional probability density function and the channel capacity estimations at large signal-to-noise ratio. We demonstrate that the correction to the channel capacity in small dimensionless dispersion parameter is quadratic and positive therefore increasing the earlier calculated capacity for a nondispersive nonlinear optical fiber channel in the intermediate power region. Also for small dispersion case we find the analytical expressions for simple correlators of the output signals in our noisy channel.

  9. Delay-limited capacity of fading multiple access and broadcast channels in the low power regime

    KAUST Repository

    Rezki, Zouheir; Alouini, Mohamed-Slim

    2015-01-01

    show that for fading channels where the MAC capacity region is strictly positive, it has a multidimensional rectangle structure and thus is simply characterized by single user capacity points. More specifically, we show that at low power, the boundary

  10. Capacity bounds for kth best path selection over generalized fading channels

    KAUST Repository

    Hanif, Muhammad Fainan; Yang, Hongchuan; Alouini, Mohamed-Slim

    2014-01-01

    Exact ergodic capacity calculation for fading wireless channels typically involves time-consuming numerical evaluation of infinite integrals. In this paper, lower and upper bounds on ergodic capacity for kth best path are presented. These bounds

  11. Low SNR capacity for MIMO Rician and Rayleigh-product fading channels with single co-channel interferer and noise

    KAUST Repository

    Zhong, Caijun

    2010-09-01

    This paper studies the ergodic capacity of multiple-input multiple-output (MIMO) systems with a single co-channel interferer in the low signal-to-noise-ratio (SNR) regime. Two MIMO models namely Rician and Rayleigh-product channels are investigated. Exact analytical expressions for the minimum energy per information bit, {Eb/N0min, and wideband slope, S0, are derived for both channels. Our results show that the minimum energy per information bit is the same for both channels while their wideband slopes differ significantly. Further, the impact of the numbers of transmit and receive antennas, the Rician K factor, the channel mean matrix and the interference-to-noise-ratio (INR) on the capacity, is addressed. Results indicate that interference degrades the capacity by increasing the required minimum energy per information bit and reducing the wideband slope. Simulation results validate our analytical results. © 2010 IEEE.

  12. 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.

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

    KAUST Repository

    Benkhelifa, Fatma; Rezki, Zouheir; Alouini, Mohamed-Slim

    2013-01-01

    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.

  14. 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.

  15. Higher order capacity statistics of multi-hop transmission systems over Rayleigh fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2012-03-01

    In this paper, we present an exact analytical expression to evaluate the higher order statistics of the channel capacity for amplify and forward (AF) multihop transmission systems operating over Rayleigh fading channels. Furthermore, we present simple and efficient closed-form expression to the higher order moments of the channel capacity of dual hop transmission system with Rayleigh fading channels. In order to analyze the behavior of the higher order capacity statistics and investigate the usefulness of the mathematical analysis, some selected numerical and simulation results are presented. Our results are found to be in perfect agreement. © 2012 IEEE.

  16. Polarized Uniform Linear Array System: Beam Radiation Pattern, Beamforming Diversity Order, and Channel Capacity

    Directory of Open Access Journals (Sweden)

    Xin Su

    2015-01-01

    Full Text Available There have been many studies regarding antenna polarization; however, there have been few publications on the analysis of the channel capacity for polarized antenna systems using the beamforming technique. According to Chung et al., the channel capacity is determined by the density of scatterers and the transmission power, which is obtained based on the assumption that scatterers are uniformly distributed on a 3D spherical scattering model. However, it contradicts the practical scenario, where scatterers may not be uniformly distributed under outdoor environment, and lacks the consideration of fading channel gain. In this study, we derive the channel capacity of polarized uniform linear array (PULA systems using the beamforming technique in a practical scattering environment. The results show that, for PULA systems, the channel capacity, which is boosted by beamforming diversity, can be determined using the channel gain, beam radiation pattern, and beamforming diversity order (BDO, where the BDO is dependent on the antenna characteristics and array configurations.

  17. Zero-Error Capacity of a Class of Timing Channels

    DEFF Research Database (Denmark)

    Kovacevic, M.; Popovski, Petar

    2014-01-01

    We analyze the problem of zero-error communication through timing channels that can be interpreted as discrete-time queues with bounded waiting times. The channel model includes the following assumptions: 1) time is slotted; 2) at most N particles are sent in each time slot; 3) every particle is ...

  18. Three-Way Channels With Multiple Unicast Sessions: Capacity Approximation via Network Transformation

    KAUST Repository

    Chaaban, Anas

    2016-09-28

    A network of three nodes mutually communicating with each other is studied. This multi-way network is a suitable model for three-user device-to-device communications. The main goal of this paper is to characterize the capacity region of the underlying Gaussian three-way channel (3WC) within a constant gap. To this end, a capacity outer bound is derived using cut-set bounds and genie-aided bounds. For achievability, the 3WC is first transformed into an equivalent star channel. This latter is then decomposed into a set of “successive” sub-channels, leading to a sub-channel allocation problem. Using backward decoding, interference neutralization, and known results on the capacity of the star-channel relying of physical-layer network coding, an achievable rate region for the 3WC is obtained. It is then shown that the achievable rate region is within a constant gap of the developed outer bound, leading to the desired capacity approximation. Interestingly, in contrast to the Gaussian two-way channel (TWC), adaptation is necessary in the 3WC. Furthermore, message splitting is another ingredient of the developed scheme for the 3WC, which is not required in the TWC. The two setups are, however, similar in terms of their sum-capacity pre-log, which is equal to 2. Finally, some interesting networks and their approximate capacities are recovered as special cases of the 3WC, such as the cooperative broadcast channel and multiple access channel.

  19. Acoustic and capacity analysis of voice academic teachers with diagnosed hyperfunctional dysphonia by using DiagnoScope Specialist software.

    Science.gov (United States)

    Zielińska-Bliźniewska, Hanna; Pietkiewicz, Piotr; Miłoński, Jarosław; Urbaniak, Joanna; Olszewski, Jurek

    2013-01-01

    The aim of the study was to assess the acoustic and capacity analyses of voice in academic teachers with hyperfunctional dysphonia using DiagnoScope Specialist software. The study covered 46 female academic teachers aged 34-48 years. The women were diagnosed with hyperfunctional dysphonia (with absence of organic pathologies). Having obtained the informed consent, a primary medical history was taken, videolaryngoscopic and stroboscopic examinations were performed and diagnostic voice acoustic and capacity analyses were carried out using DiagnoScope Specialist software. The acoustic analysis carried out of academic teachers with diagnosed hyperfunctional dysphonia showed enhancement in the following parameters: fundamental frequency (FO) by 1.2%; relative average perturbation (Jitter by 100.0% and RAP by 81.8%); relative amplitude perturbation quotient (APQ) by 2.9%; non-harmonic to harmonic ratio (U2H) by 16.0%; and noise to harmonic ratio (NHR) by 13.4%. A decrease of 2.5% from normal values was noted in relative amplitude perturbation (Shimmer). Formant frequencies also showed reduction (F1 by 10.7%, F2 by 5.1%, F3 by 2.2%, and F4 by 3.5%). The harmonic perturbation quotient (HPQ) was 0.8% lower and the residual harmonic perturbation quotient (RHPQ) 16.8% lower, with the residual to harmonic (R2H) decreasing by 35.1 per cent; the sub-harmonic to harmonic (S2H) by 2.4%; and the Yanagihara coefficient by 20.2%. The capacity analysis with the DiagnoScope Specialist software showed figures significantly lower than normal values of the following parameters: phonation time, true phonation time, phonation break coefficients, vocal capacity coefficient and mean vocal capacity. Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  20. Delay-limited capacity of fading multiple access and broadcast channels in the low power regime

    KAUST Repository

    Rezki, Zouheir

    2015-09-11

    We study delay-limited (also called zero-outage) capacity region of the fading multi-access channel (MAC) with Gaussian noise and perfect channel state information (CSI) at the receiver and at the transmitters (CSI-TR), in the low-power regime. We show that for fading channels where the MAC capacity region is strictly positive, it has a multidimensional rectangle structure and thus is simply characterized by single user capacity points. More specifically, we show that at low power, 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 the Gaussian MAC and broadcast channels (BC), we show that time-sharing (or time division multiple access (TDMA)) is asymptotically optimal. © 2015 IEEE.

  1. Approximating the constellation constrained capacity of the MIMO channel with discrete input

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Forchhammer, Søren; Larsen, Knud J.

    2015-01-01

    In this paper the capacity of a Multiple Input Multiple Output (MIMO) channel is considered, subject to average power constraint, for multi-dimensional discrete input, in the case when no channel state information is available at the transmitter. We prove that when the constellation size grows, t...... for the equivalent orthogonal channel, obtained by the singular value decomposition. Furthermore, lower bounds on the constrained capacity are derived for the cases of square and tall MIMO matrix, by optimizing the constellation for the equivalent channel, obtained by QR decomposition....

  2. A new simple model for composite fading channels: Second order statistics and channel capacity

    KAUST Repository

    Yilmaz, Ferkan; Alouini, Mohamed-Slim

    2010-01-01

    In this paper, we introduce the most general composite fading distribution to model the envelope and the power of the received signal in such fading channels as millimeter wave (60 GHz or above) fading channels and free-space optical channels, which

  3. Novel asymptotic results on the high-order statistics of the channel capacity over generalized fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2012-06-01

    The exact analysis of the higher-order statistics of the channel capacity (i.e., higher-order ergodic capacity) often leads to complicated expressions involving advanced special functions. In this paper, we provide a generic framework for the computation of the higher-order statistics of the channel capacity over generalized fading channels. As such, this novel framework for the higher-order statistics results in simple, closed-form expressions which are shown to be asymptotically tight bounds in the high signal-to-noise ratio (SNR) regime of a variety of fading environment. In addition, it reveals the existence of differences (i.e., constant capacity gaps in log-domain) among different fading environments. By asymptotically tight bound we mean that the high SNR limit of the difference between the actual higher-order statistics of the channel capacity and its asymptotic bound (i.e., lower bound) tends to zero. The mathematical formalism is illustrated with some selected numerical examples that validate the correctness of our newly derived results. © 2012 IEEE.

  4. On the secrecy capacity of the broadcast wiretap channel with limited CSI feedback

    KAUST Repository

    Hyadi, Amal

    2016-10-27

    In this paper, we investigate the problem of secure broadcasting over block-fading channels with limited channel knowledge at the transmitter. More particularly, we analyze the effect of having imperfect channel state information (CSI) via a finite rate feedback on the throughput of a broadcast channel where the transmission is intended for multiple legitimate receivers in the presence of an eavesdropper. First, we partially characterize the ergodic secrecy capacity of the system when the source broadcasts the same information to all the receivers, i.e., common message transmission. Then, we look at the independent messages case, where the transmitter broadcasts multiple independent messages to the legitimate receivers. For this case, we present lower and upper bounds on the ergodic secrecy sum-capacity. In both scenarios, we show that the proposed lower and upper bounds coincide asymptotically as the capacity of the feedback links becomes large, hence, fully characterizing the secrecy capacity in this case.

  5. On the secrecy capacity of the broadcast wiretap channel with limited CSI feedback

    KAUST Repository

    Hyadi, Amal; Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    In this paper, we investigate the problem of secure broadcasting over block-fading channels with limited channel knowledge at the transmitter. More particularly, we analyze the effect of having imperfect channel state information (CSI) via a finite rate feedback on the throughput of a broadcast channel where the transmission is intended for multiple legitimate receivers in the presence of an eavesdropper. First, we partially characterize the ergodic secrecy capacity of the system when the source broadcasts the same information to all the receivers, i.e., common message transmission. Then, we look at the independent messages case, where the transmitter broadcasts multiple independent messages to the legitimate receivers. For this case, we present lower and upper bounds on the ergodic secrecy sum-capacity. In both scenarios, we show that the proposed lower and upper bounds coincide asymptotically as the capacity of the feedback links becomes large, hence, fully characterizing the secrecy capacity in this case.

  6. A Unified Simulation Approach for the Fast Outage Capacity Evaluation over Generalized Fading Channels

    KAUST Repository

    Rached, Nadhir B.; Kammoun, Abla; Alouini, Mohamed-Slim; Tempone, Raul

    2016-01-01

    The outage capacity (OC) is among the most important performance metrics of communication systems over fading channels. The evaluation of the OC, when equal gain combining (EGC) or maximum ratio combining (MRC) diversity techniques are employed

  7. MIMO Intensity-Modulation Channels: Capacity Bounds and High SNR Characterization

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    The capacity of MIMO intensity modulation channels is studied. The nonnegativity of the transmit signal (intensity) poses a challenge on the precoding of the transmit signal, which limits the applicability of classical schemes in this type

  8. Low SNR Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels

    KAUST Repository

    Benkhelifa, Fatma; Alouini, Mohamed-Slim; Rezki, Zouheir

    2013-01-01

    free space optical communication systems over Gamma-Gamma atmospheric turbulence fading channels with perfect channel state information at both the transmitter and the receiver. In our framework, we mainly focus on the low signal-to-noise ratio range and show that the ergodic capacity scales proportionally to SNR log^4(1/SNR). We show also that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-o ff power control scheme.

  9. Eigenstructures of MIMO Fading Channel Correlation Matrices and Optimum Linear Precoding Designs for Maximum Ergodic Capacity

    Directory of Open Access Journals (Sweden)

    Hamid Reza Bahrami

    2007-01-01

    Full Text Available The ergodic capacity of MIMO frequency-flat and -selective channels depends greatly on the eigenvalue distribution of spatial correlation matrices. Knowing the eigenstructure of correlation matrices at the transmitter is very important to enhance the capacity of the system. This fact becomes of great importance in MIMO wireless systems where because of the fast changing nature of the underlying channel, full channel knowledge is difficult to obtain at the transmitter. In this paper, we first investigate the effect of eigenvalues distribution of spatial correlation matrices on the capacity of frequency-flat and -selective channels. Next, we introduce a practical scheme known as linear precoding that can enhance the ergodic capacity of the channel by changing the eigenstructure of the channel by applying a linear transformation. We derive the structures of precoders using eigenvalue decomposition and linear algebra techniques in both cases and show their similarities from an algebraic point of view. Simulations show the ability of this technique to change the eigenstructure of the channel, and hence enhance the ergodic capacity considerably.

  10. On the Secrecy Capacity of the Multiple-Antenna Wiretap Channel with Limited CSI Feedback

    KAUST Repository

    Hyadi, Amal; Rezki, Zouheir; Alouini, Mohamed-Slim

    2015-01-01

    We study the ergodic secrecy capacity of a block fading wiretap channel when there are multiple antennas at the transmitter, the legitimate receiver and the eavesdropper. We consider that the receivers are aware of their respective channel matrices while the transmitter is only provided by a B-bits feedback of the main channel state information. The feedback bits are sent by the legitimate receiver, at the beginning of each fading block, over an error free public link with limited capacity. Assuming an average transmit power constraint, we provide an upper and a lower bounds on the ergodic secrecy capacity. Then, we present a framework to design the optimal codebooks for feedback and transmission. In addition, we show that the proposed lower and upper bounds coincide asymptotically as the capacity of the feedback link becomes large; hence, fully characterizing the secrecy capacity in this case.

  11. On the Secrecy Capacity of the Multiple-Antenna Wiretap Channel with Limited CSI Feedback

    KAUST Repository

    Hyadi, Amal

    2015-12-01

    We study the ergodic secrecy capacity of a block fading wiretap channel when there are multiple antennas at the transmitter, the legitimate receiver and the eavesdropper. We consider that the receivers are aware of their respective channel matrices while the transmitter is only provided by a B-bits feedback of the main channel state information. The feedback bits are sent by the legitimate receiver, at the beginning of each fading block, over an error free public link with limited capacity. Assuming an average transmit power constraint, we provide an upper and a lower bounds on the ergodic secrecy capacity. Then, we present a framework to design the optimal codebooks for feedback and transmission. In addition, we show that the proposed lower and upper bounds coincide asymptotically as the capacity of the feedback link becomes large; hence, fully characterizing the secrecy capacity in this case.

  12. Three-Way Channels With Multiple Unicast Sessions: Capacity Approximation via Network Transformation

    KAUST Repository

    Chaaban, Anas; Maier, Henning; Sezgin, Aydin; Mathar, Rudolf

    2016-01-01

    of the underlying Gaussian three-way channel (3WC) within a constant gap. To this end, a capacity outer bound is derived using cut-set bounds and genie-aided bounds. For achievability, the 3WC is first transformed into an equivalent star channel. This latter

  13. Low-SNR Capacity of Parallel IM-DD Optical Wireless Channels

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    The capacity of parallel intensity-modulation and direct-detection (IM-DD) optical wireless channels with total average intensity and per-channel peak intensity constraints is studied. The optimal intensity allocation at low signal-to-noise ratio

  14. User Influence on MIMO Channel Capacity for Handsets in Data Mode Operation

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Yanakiev, Boyan Radkov; Bonev, Ivan Bonev

    2012-01-01

    The current paper concerns realistic evaluation of the capacity of the MIMO channel between a BS and handheld device, such as a PDA or smartphone, held in front of the user’s body (data mode). The work is based on measurements of the MIMO channel between two widely separated BSs in a micro...

  15. On the ergodic secret message capacity of the wiretap channel with finite-rate feedback

    KAUST Repository

    Rezki, Zouheir

    2012-07-01

    We study the secret message capacity of an ergodic block fading wiretap channel with partial channel state information at the transmitter and perfect channel state information at the receivers. We consider that in addition to the statistics of the main and the eavesdropper channel state information (CSI), the sender is provided by the legitimate receiver with a q-bit feedback, at the beginning of each coherence block, through an error-free feedback channel, with capacity q bits. We establish upper and lower bounds on the secrecy capacity. We show that a positive secrecy rate is achievable even when the feedback is at the end of each coherence block and q = 1. We also show that the lower and the upper bounds coincide asymptotically as q → ∞. Finally, asymptotic analysis at high Signal-to-Noise Ratio (SNR) are presented where it is found that the capacity is bounded at high-SNR and present a simple suboptimal scalar quantizer that is capacity achieving, without the need of any numerical optimization, as q → ∞. When applied to Rayleigh fading channels, we show that, at high-SNR, a 4-bit feedback achieves 90% of the secrecy capacity when perfect main CSI is available at the transmitter. © 2012 IEEE.

  16. On the ergodic secret message capacity of the wiretap channel with finite-rate feedback

    KAUST Repository

    Rezki, Zouheir; Khisti, Ashish J.; Alouini, Mohamed-Slim

    2012-01-01

    We study the secret message capacity of an ergodic block fading wiretap channel with partial channel state information at the transmitter and perfect channel state information at the receivers. We consider that in addition to the statistics of the main and the eavesdropper channel state information (CSI), the sender is provided by the legitimate receiver with a q-bit feedback, at the beginning of each coherence block, through an error-free feedback channel, with capacity q bits. We establish upper and lower bounds on the secrecy capacity. We show that a positive secrecy rate is achievable even when the feedback is at the end of each coherence block and q = 1. We also show that the lower and the upper bounds coincide asymptotically as q → ∞. Finally, asymptotic analysis at high Signal-to-Noise Ratio (SNR) are presented where it is found that the capacity is bounded at high-SNR and present a simple suboptimal scalar quantizer that is capacity achieving, without the need of any numerical optimization, as q → ∞. When applied to Rayleigh fading channels, we show that, at high-SNR, a 4-bit feedback achieves 90% of the secrecy capacity when perfect main CSI is available at the transmitter. © 2012 IEEE.

  17. Nonadditivity of quantum capacities of quantum multiple-access channels and the butterfly network

    International Nuclear Information System (INIS)

    Huang Peng; He Guangqiang; Zhu Jun; Zeng Guihua

    2011-01-01

    Multipartite quantum information transmission without additional classical resources is investigated. We show purely quantum superadditivity of quantum capacity regions of quantum memoryless multiple-access (MA) channels, which are not entanglement breaking. Also, we find that the superadditivity holds when the MA channel extends to the quantum butterfly network, which can achieve quantum network coding. The present widespread effects for the channels which enable entanglement distribution have not been revealed for multipartite scenarios.

  18. Asymptotic Ergodic Capacity Analysis of Composite Lognormal Shadowed Channels

    KAUST Repository

    Ansari, Imran Shafique

    2015-05-01

    Capacity analysis of composite lognormal (LN) shadowed links, such as Rician-LN, Gamma-LN, and Weibull-LN, is addressed in this work. More specifically, an exact closed-form expression for the moments of the end-to-end signal-to-noise ratio (SNR) of a single composite link transmission system is presented in terms of well- known elementary functions. Capitalizing on these new moments expressions, we present asymptotically tight lower bounds for the ergodic capacity at high SNR. All the presented results are verified via computer-based Monte-Carlo simulations. © 2015 IEEE.

  19. MIMO capacity for deterministic channel models: sublinear growth

    DEFF Research Database (Denmark)

    Bentosela, Francois; Cornean, Horia; Marchetti, Nicola

    2013-01-01

    . In the current paper, we apply those results in order to study the (Shannon-Foschini) capacity behavior of a MIMO system as a function of the deterministic spread function of the environment and the number of transmitting and receiving antennas. The antennas are assumed to fill in a given fixed volume. Under...... some generic assumptions, we prove that the capacity grows much more slowly than linearly with the number of antennas. These results reinforce previous heuristic results obtained from statistical models of the transfer matrix, which also predict a sublinear behavior....

  20. Asymptotic Ergodic Capacity Analysis of Composite Lognormal Shadowed Channels

    KAUST Repository

    Ansari, Imran Shafique; Alouini, Mohamed-Slim

    2015-01-01

    Capacity analysis of composite lognormal (LN) shadowed links, such as Rician-LN, Gamma-LN, and Weibull-LN, is addressed in this work. More specifically, an exact closed-form expression for the moments of the end-to-end signal-to-noise ratio (SNR) of a single composite link transmission system is presented in terms of well- known elementary functions. Capitalizing on these new moments expressions, we present asymptotically tight lower bounds for the ergodic capacity at high SNR. All the presented results are verified via computer-based Monte-Carlo simulations. © 2015 IEEE.

  1. Reliability Capacity of Half-Duplex Channels with Strict Deadlines

    DEFF Research Database (Denmark)

    Costa, Rui; Roetter, Daniel Enrique Lucani; Vinhoza, Tiago

    2015-01-01

    A fundamental characterization of a half-duplex wireless system with packet losses under traffic with hard deadlines is instrumental to understanding and developing efficient, coding aware policies for real-time applications. We set forth the concept of reliability capacity with a limited number ...

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

    KAUST Repository

    Rezki, Zouheir; Alouini, Mohamed-Slim

    2013-01-01

    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

  3. Fundamental Limits of Parallel Optical Wireless Channels: Capacity Results and Outage Formulation

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    Multi-channel (MC) optical wireless communication (OWC) systems employing wave-division multiplexing for outdoors free-space optical communications, or multi-user timedivision multiple access for indoors visible-light communications, e.g., can be modeled as parallel channels. Multi-input multioutput OWC systems can also be transformed, possibly with some performance loss, to parallel channels using pre-/postcoding. Studying the performance of such MC-OWC systems requires characterizing the capacity of the underlying parallel channels. In this paper, upper and lower bounds on the capacity of constant parallel OWC channels with a total average intensity constraint are derived. Then, the paper focuses on finding intensity allocations that maximize the lower bounds given channel-state information at the transmitter (CSIT). Due to its nonconvexity, the KKT conditions are used to describe a list of candidate allocations. Instead searching exhaustively for the best solution, low-complexity near-optimal algorithms are proposed. The resulting optimized lower bound nearly coincides with capacity at high signal-to-noise ratio (SNR). Under a quasi-static channel model and in the absence of CSIT, outage probability upper and lower bounds are derived. Those bounds also meet at high SNR, thus characterizing the outage capacity in this regime. Finally, the results are extended to a system with both average and peak intensity constraints.

  4. Fundamental Limits of Parallel Optical Wireless Channels: Capacity Results and Outage Formulation

    KAUST Repository

    Chaaban, Anas

    2016-10-26

    Multi-channel (MC) optical wireless communication (OWC) systems employing wave-division multiplexing for outdoors free-space optical communications, or multi-user timedivision multiple access for indoors visible-light communications, e.g., can be modeled as parallel channels. Multi-input multioutput OWC systems can also be transformed, possibly with some performance loss, to parallel channels using pre-/postcoding. Studying the performance of such MC-OWC systems requires characterizing the capacity of the underlying parallel channels. In this paper, upper and lower bounds on the capacity of constant parallel OWC channels with a total average intensity constraint are derived. Then, the paper focuses on finding intensity allocations that maximize the lower bounds given channel-state information at the transmitter (CSIT). Due to its nonconvexity, the KKT conditions are used to describe a list of candidate allocations. Instead searching exhaustively for the best solution, low-complexity near-optimal algorithms are proposed. The resulting optimized lower bound nearly coincides with capacity at high signal-to-noise ratio (SNR). Under a quasi-static channel model and in the absence of CSIT, outage probability upper and lower bounds are derived. Those bounds also meet at high SNR, thus characterizing the outage capacity in this regime. Finally, the results are extended to a system with both average and peak intensity constraints.

  5. Low SNR Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels

    KAUST Repository

    Benkhelifa, Fatma

    2013-01-27

    In this paper, we study the ergodic capacity of free space optical communication systems over Gamma-Gamma atmospheric turbulence fading channels with perfect channel state information at both the transmitter and the receiver. In our framework, we mainly focus on the low signal-to-noise ratio range and show that the ergodic capacity scales proportionally to SNR log^4(1/SNR). We show also that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-o ff power control scheme.

  6. Low SNR Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels

    KAUST Repository

    Benkhelifa, Fatma

    2013-02-23

    In this paper, we study the ergodic capacity of free space optical communication systems over Gamma-Gamma atmospheric turbulence fading channels with perfect channel state information at both the transmitter and the receiver. In our framework, we mainly focus on the low signal-to-noise ratio range and show that the ergodic capacity scales proportionally to SNR log^4(1/SNR). We show also that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-off power control scheme.

  7. Low SNR Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels

    KAUST Repository

    Benkhelifa, Fatma; Alouini, Mohamed-Slim; Rezki, Zouheir

    2013-01-01

    In this paper, we study the ergodic capacity of free space optical communication systems over Gamma-Gamma atmospheric turbulence fading channels with perfect channel state information at both the transmitter and the receiver. In our framework, we mainly focus on the low signal-to-noise ratio range and show that the ergodic capacity scales proportionally to SNR log^4(1/SNR). We show also that one-bit CSI feedback at the transmitter is enough to achieve this capacity using an on-off power control scheme.

  8. Capacity bounds for kth best path selection over generalized fading channels

    KAUST Repository

    Hanif, Muhammad Fainan

    2014-02-01

    Exact ergodic capacity calculation for fading wireless channels typically involves time-consuming numerical evaluation of infinite integrals. In this paper, lower and upper bounds on ergodic capacity for kth best path are presented. These bounds have simple analytic expressions which allow their fast evaluation. Numerical results show that the newly proposed bounds closely approximate the exact ergodic capacity for a large variety of system configurations. © 1997-2012 IEEE.

  9. Capacity estimation and verification of quantum channels with arbitrarily correlated errors.

    Science.gov (United States)

    Pfister, Corsin; Rol, M Adriaan; Mantri, Atul; Tomamichel, Marco; Wehner, Stephanie

    2018-01-02

    The central figure of merit for quantum memories and quantum communication devices is their capacity to store and transmit quantum information. Here, we present a protocol that estimates a lower bound on a channel's quantum capacity, even when there are arbitrarily correlated errors. One application of these protocols is to test the performance of quantum repeaters for transmitting quantum information. Our protocol is easy to implement and comes in two versions. The first estimates the one-shot quantum capacity by preparing and measuring in two different bases, where all involved qubits are used as test qubits. The second verifies on-the-fly that a channel's one-shot quantum capacity exceeds a minimal tolerated value while storing or communicating data. We discuss the performance using simple examples, such as the dephasing channel for which our method is asymptotically optimal. Finally, we apply our method to a superconducting qubit in experiment.

  10. Ergodic secret message capacity of the wiretap channel with finite-rate feedback

    KAUST Repository

    Rezki, Zouheir

    2014-06-01

    We study the secret message capacity of an ergodic block fading wiretap channel with partial channel state information at the transmitter and perfect channel state information at the receivers, under both a short term power constraint (STPC) and a long term power constraint (LTPC). We consider that in addition to the statistics of the main and the eavesdropper channel state information (CSI), the sender is provided by the legitimate receiver with a q-bit feedback, at the beginning of each coherence block, through an error-free public channel, with capacity q bits. We establish upper and lower bounds on the secrecy capacity. We show that the lower and the upper bounds coincide asymptotically as q → ∞. When applied to Rayleigh fading channels, we show that, a 4-bit feedback achieves about 90% of the secrecy capacity when perfect main CSI is available at the transmitter. Finally, asymptotic analysis at high and low Signal-to-Noise Ratio (SNR) is presented. It is found that the capacity is bounded at high-SNR, whereas at asymptotically low-SNR, the lower bounds and the upper bound scale linearly with SNR under STPC. Furthermore, subject to LTPC, the capacity at low-SNR is equal to the capacity of the main channel without secrecy constraint and with perfect CSI at both the transmitter and the receiver, under a mild condition on the fading statistics. We also show that a positive secrecy rate is achievable even when the feedback is at the end of each coherence block and q=1. © 2002-2012 IEEE.

  11. Ergodic secret message capacity of the wiretap channel with finite-rate feedback

    KAUST Repository

    Rezki, Zouheir; Khisti, Ashish J.; Alouini, Mohamed-Slim

    2014-01-01

    We study the secret message capacity of an ergodic block fading wiretap channel with partial channel state information at the transmitter and perfect channel state information at the receivers, under both a short term power constraint (STPC) and a long term power constraint (LTPC). We consider that in addition to the statistics of the main and the eavesdropper channel state information (CSI), the sender is provided by the legitimate receiver with a q-bit feedback, at the beginning of each coherence block, through an error-free public channel, with capacity q bits. We establish upper and lower bounds on the secrecy capacity. We show that the lower and the upper bounds coincide asymptotically as q → ∞. When applied to Rayleigh fading channels, we show that, a 4-bit feedback achieves about 90% of the secrecy capacity when perfect main CSI is available at the transmitter. Finally, asymptotic analysis at high and low Signal-to-Noise Ratio (SNR) is presented. It is found that the capacity is bounded at high-SNR, whereas at asymptotically low-SNR, the lower bounds and the upper bound scale linearly with SNR under STPC. Furthermore, subject to LTPC, the capacity at low-SNR is equal to the capacity of the main channel without secrecy constraint and with perfect CSI at both the transmitter and the receiver, under a mild condition on the fading statistics. We also show that a positive secrecy rate is achievable even when the feedback is at the end of each coherence block and q=1. © 2002-2012 IEEE.

  12. Shannon Meets Fick on the Microfluidic Channel: Diffusion Limit to Sum Broadcast Capacity for Molecular Communication.

    Science.gov (United States)

    Bicen, A Ozan; Lehtomaki, Janne J; Akyildiz, Ian F

    2018-03-01

    Molecular communication (MC) over a microfluidic channel with flow is investigated based on Shannon's channel capacity theorem and Fick's laws of diffusion. Specifically, the sum capacity for MC between a single transmitter and multiple receivers (broadcast MC) is studied. The transmitter communicates by using different types of signaling molecules with each receiver over the microfluidic channel. The transmitted molecules propagate through microfluidic channel until reaching the corresponding receiver. Although the use of different types of molecules provides orthogonal signaling, the sum broadcast capacity may not scale with the number of the receivers due to physics of the propagation (interplay between convection and diffusion based on distance). In this paper, the performance of broadcast MC on a microfluidic chip is characterized by studying the physical geometry of the microfluidic channel and leveraging the information theory. The convergence of the sum capacity for microfluidic broadcast channel is analytically investigated based on the physical system parameters with respect to the increasing number of molecular receivers. The analysis presented here can be useful to predict the achievable information rate in microfluidic interconnects for the biochemical computation and microfluidic multi-sample assays.

  13. 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.

  14. 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.

  15. On the computation of the higher-order statistics of the channel capacity over generalized fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2012-12-01

    The higher-order statistics (HOS) of the channel capacity μn=E[logn (1+γ end)], where n ∈ N denotes the order of the statistics, has received relatively little attention in the literature, due in part to the intractability of its analysis. In this letter, we propose a novel and unified analysis, which is based on the moment generating function (MGF) technique, to exactly compute the HOS of the channel capacity. More precisely, our mathematical formalism can be readily applied to maximal-ratio-combining (MRC) receivers operating in generalized fading environments. The mathematical formalism is illustrated by some numerical examples focusing on the correlated generalized fading environments. © 2012 IEEE.

  16. On the computation of the higher-order statistics of the channel capacity over generalized fading channels

    KAUST Repository

    Yilmaz, Ferkan; Alouini, Mohamed-Slim

    2012-01-01

    The higher-order statistics (HOS) of the channel capacity μn=E[logn (1+γ end)], where n ∈ N denotes the order of the statistics, has received relatively little attention in the literature, due in part to the intractability of its analysis. In this letter, we propose a novel and unified analysis, which is based on the moment generating function (MGF) technique, to exactly compute the HOS of the channel capacity. More precisely, our mathematical formalism can be readily applied to maximal-ratio-combining (MRC) receivers operating in generalized fading environments. The mathematical formalism is illustrated by some numerical examples focusing on the correlated generalized fading environments. © 2012 IEEE.

  17. Capacity of a bosonic memory channel with Gauss-Markov noise

    International Nuclear Information System (INIS)

    Schaefer, Joachim; Daems, David; Karpov, Evgueni; Cerf, Nicolas J.

    2009-01-01

    We address the classical capacity of a quantum bosonic memory channel with additive noise, subject to an input energy constraint. The memory is modeled by correlated noise emerging from a Gauss-Markov process. Under reasonable assumptions, we show that the optimal modulation results from a 'quantum water-filling' solution above a certain input energy threshold, similar to the optimal modulation for parallel classical Gaussian channels. We also derive analytically the optimal multimode input state above this threshold, which enables us to compute the capacity of this memory channel in the limit of an infinite number of modes. The method can also be applied to a more general noise environment which is constructed by a stationary Gauss process. The extension of our results to the case of broadband bosonic channels with colored Gaussian noise should also be straightforward.

  18. Exact capacity analysis of multihop transmission over amplify-and-forward relay fading channels

    KAUST Repository

    Yilmaz, Ferkan; Kucur, Oǧuz; Alouini, Mohamed-Slim

    2010-01-01

    In this paper, we propose an analytical framework on the exact computation of the average capacity of multihop transmission over amplify-and-forward relay fading channels. Our approach relies on the algebraic combination of Mellin and Laplace transforms to obtain exact single integral expressions which can be easily computed by Gauss-Chebyshev Quadrature (GCQ) rule. As such, the derived results are a convenient tool to analyze the average capacity of multihop transmission over amplify-and-forward relay fading channels. As an application of the analytical framework on the exact computation of the average capacity of multihop transmission, some examples are accentuated for generalized Nakagami-m fading channels. Numerical and simulation results, performed to verify the correctness of the proposed formulation, are in perfect agreement. ©2010 IEEE.

  19. On the BER and capacity analysis of MIMO MRC systems with channel estimation error

    KAUST Repository

    Yang, Liang

    2011-10-01

    In this paper, we investigate the effect of channel estimation error on the capacity and bit-error rate (BER) of a multiple-input multiple-output (MIMO) transmit maximal ratio transmission (MRT) and receive maximal ratio combining (MRC) systems over uncorrelated Rayleigh fading channels. We first derive the ergodic (average) capacity expressions for such systems when power adaptation is applied at the transmitter. The exact capacity expression for the uniform power allocation case is also presented. Furthermore, to investigate the diversity order of MIMO MRT-MRC scheme, we derive the BER performance under a uniform power allocation policy. We also present an asymptotic BER performance analysis for the MIMO MRT-MRC system with multiuser diversity. The numerical results are given to illustrate the sensitivity of the main performance to the channel estimation error and the tightness of the approximate cutoff value. © 2011 IEEE.

  20. Gaussian capacity of the quantum bosonic memory channel with additive correlated Gaussian noise

    International Nuclear Information System (INIS)

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

    2011-01-01

    We present an algorithm for calculation of the Gaussian classical capacity of a quantum bosonic memory channel with additive Gaussian noise. The algorithm, restricted to Gaussian input states, is applicable to all channels with noise correlations obeying certain conditions and works in the full input energy domain, beyond previous treatments of this problem. As an illustration, we study the optimal input states and capacity of a quantum memory channel with Gauss-Markov noise [J. Schaefer, Phys. Rev. A 80, 062313 (2009)]. We evaluate the enhancement of the transmission rate when using these optimal entangled input states by comparison with a product coherent-state encoding and find out that such a simple coherent-state encoding achieves not less than 90% of the capacity.

  1. Exact capacity analysis of multihop transmission over amplify-and-forward relay fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2010-09-01

    In this paper, we propose an analytical framework on the exact computation of the average capacity of multihop transmission over amplify-and-forward relay fading channels. Our approach relies on the algebraic combination of Mellin and Laplace transforms to obtain exact single integral expressions which can be easily computed by Gauss-Chebyshev Quadrature (GCQ) rule. As such, the derived results are a convenient tool to analyze the average capacity of multihop transmission over amplify-and-forward relay fading channels. As an application of the analytical framework on the exact computation of the average capacity of multihop transmission, some examples are accentuated for generalized Nakagami-m fading channels. Numerical and simulation results, performed to verify the correctness of the proposed formulation, are in perfect agreement. ©2010 IEEE.

  2. An MGF-based capacity analysis of equal gain combining over fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2010-09-01

    Exact average capacity results for L-branch coherent equal-gain combining (EGC) in correlated and uncorrelated fading channels are not known. This paper develops a novel framework (approach) for capacity analysis of L-branch EGC in generalized fading channels. In addition, Gamma shadowed generalized Nakagami-m fading model is proposed in order to statistically model the fading environments in high frequencies such as 60 GHz and above. Some simulations are carried out and then the obtained results are accentuated by means of numerical analysis based on the proposed framework. Numerical and simulation results, performed to verify the correctness of the proposed framework, are in perfect agreement. ©2010 IEEE.

  3. An MGF-based capacity analysis of equal gain combining over fading channels

    KAUST Repository

    Yilmaz, Ferkan; Alouini, Mohamed-Slim

    2010-01-01

    Exact average capacity results for L-branch coherent equal-gain combining (EGC) in correlated and uncorrelated fading channels are not known. This paper develops a novel framework (approach) for capacity analysis of L-branch EGC in generalized fading channels. In addition, Gamma shadowed generalized Nakagami-m fading model is proposed in order to statistically model the fading environments in high frequencies such as 60 GHz and above. Some simulations are carried out and then the obtained results are accentuated by means of numerical analysis based on the proposed framework. Numerical and simulation results, performed to verify the correctness of the proposed framework, are in perfect agreement. ©2010 IEEE.

  4. Capacity of spectrum sharing Cognitive Radio systems over Nakagami fading channels at low SNR

    KAUST Repository

    Sboui, Lokman

    2013-06-01

    In this paper, we study the ergodic capacity of Cognitive Radio (CR) spectrum sharing systems at low power regime. We focus on Nakagami fading channels. We formally define the low power regime and present closed form expressions of the capacity in the low power regime under various types of interference and/or power constraints, depending on the available channel state information (CSI) of the cross link (CL) between the secondary user transmitter and the primary user receiver. We explicitly characterize two regimes where either the interference constraint or the power constraint dictates the optimal power profile. Our framework also highlights the effects of different fading parameters on the secondary link ergodic capacity. Interestingly, we show that the low power regime analysis provides a specific insight on the capacity behavior of CR that has not been reported by previous studies. © 2013 IEEE.

  5. The Approximate Capacity Region of the Symmetric $K$-user Gaussian Interference Channel with Strong Interference

    KAUST Repository

    Chaaban, Anas; Sezgin, Aydin

    2016-01-01

    The symmetric K-user interference channel is studied with the goal of characterizing its capacity region in the strong interference regime within a constant gap. The achievable rate region of a scheme combining rate-splitting at the transmitters and interference alignment and successive decoding/computation at the receivers is derived. Next it is shown that this scheme achieves the so-called greedy-max corner points of the capacity region within a constant gap. By combining this result with previous results by Ordentlich et al. on the sum-capacity of the symmetric interference channel, a constant gap characterization of the capacity region for the strong interference regime is obtained. This leads to the first approximate characterization of the capacity region of the symmetric K-user IC. Furthermore, a new scheme that achieves the sum-capacity of the channel in the strong interference regime within a constant gap is also proposed, and the corresponding gap is calculated. The advantage of the new scheme is that it leads to a characterization within a constant gap without leaving an outage set contrary to the scheme by Ordentlich et al..

  6. The Approximate Capacity Region of the Symmetric $K$-user Gaussian Interference Channel with Strong Interference

    KAUST Repository

    Chaaban, Anas

    2016-03-01

    The symmetric K-user interference channel is studied with the goal of characterizing its capacity region in the strong interference regime within a constant gap. The achievable rate region of a scheme combining rate-splitting at the transmitters and interference alignment and successive decoding/computation at the receivers is derived. Next it is shown that this scheme achieves the so-called greedy-max corner points of the capacity region within a constant gap. By combining this result with previous results by Ordentlich et al. on the sum-capacity of the symmetric interference channel, a constant gap characterization of the capacity region for the strong interference regime is obtained. This leads to the first approximate characterization of the capacity region of the symmetric K-user IC. Furthermore, a new scheme that achieves the sum-capacity of the channel in the strong interference regime within a constant gap is also proposed, and the corresponding gap is calculated. The advantage of the new scheme is that it leads to a characterization within a constant gap without leaving an outage set contrary to the scheme by Ordentlich et al..

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

    KAUST Repository

    Rezki, Zouheir; Alouini, Mohamed-Slim

    2012-01-01

    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

  8. Geometry of human vocal folds and glottal channel for mathematical and biomechanical modeling of voice production

    Czech Academy of Sciences Publication Activity Database

    Šidlof, Petr; Švec, J. G.; Horáček, Jaromír; Veselý, Jan; Klepáček, I.; Havlík, R.

    2008-01-01

    Roč. 41, - (2008), s. 985-995 ISSN 0021-9290 R&D Projects: GA AV ČR IAA2076401 Institutional research plan: CEZ:AV0Z20760514 Keywords : vocal fold geometry * glottal channel shape * quantitative description Subject RIV: BI - Acoustics Impact factor: 2.784, year: 2008

  9. On the low SNR capacity of log-normal turbulence channels with full CSI

    KAUST Repository

    Benkhelifa, Fatma; Tall, Abdoulaye; Rezki, Zouheir; Alouini, Mohamed-Slim

    2014-01-01

    In this paper, we characterize the low signal-To-noise ratio (SNR) capacity of wireless links undergoing the log-normal turbulence when the channel state information (CSI) is perfectly known at both the transmitter and the receiver. We derive a closed form asymptotic expression of the capacity and we show that it scales essentially as λ SNR where λ is the water-filling level satisfying the power constraint. An asymptotically closed-form expression of λ is also provided. Using this framework, we also propose an on-off power control scheme which is capacity-achieving in the low SNR regime.

  10. On the low SNR capacity of log-normal turbulence channels with full CSI

    KAUST Repository

    Benkhelifa, Fatma

    2014-09-01

    In this paper, we characterize the low signal-To-noise ratio (SNR) capacity of wireless links undergoing the log-normal turbulence when the channel state information (CSI) is perfectly known at both the transmitter and the receiver. We derive a closed form asymptotic expression of the capacity and we show that it scales essentially as λ SNR where λ is the water-filling level satisfying the power constraint. An asymptotically closed-form expression of λ is also provided. Using this framework, we also propose an on-off power control scheme which is capacity-achieving in the low SNR regime.

  11. On the BER and capacity analysis of MIMO MRC systems with channel estimation error

    KAUST Repository

    Yang, Liang; Alouini, Mohamed-Slim

    2011-01-01

    In this paper, we investigate the effect of channel estimation error on the capacity and bit-error rate (BER) of a multiple-input multiple-output (MIMO) transmit maximal ratio transmission (MRT) and receive maximal ratio combining (MRC) systems over

  12. On the Ergodic Capacity of Dual-Branch Correlated Log-Normal Fading Channels with Applications

    KAUST Repository

    Al-Quwaiee, Hessa; Alouini, Mohamed-Slim

    2015-01-01

    Closed-form expressions of the ergodic capacity of independent or correlated diversity branches over Log-Normal fading channels are not available in the literature. Thus, it is become of an interest to investigate the behavior of such metric at high

  13. Range extension and channel capacity increase in impulse-radio ultra-wideband communications

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Yu, Xianbin; Caballero Jambrina, Antonio

    2010-01-01

    We theoretically analyze the channel capacity of a 5th-order Gaussian pulse-based ultra-wideband (UWB) system and experimentally demonstrate 2 Gbit/s UWB-over-fiber transmission systems incorporating wireless transmission. Both electrical and photonic UWB pulse generation methods are employed...

  14. Low-SNR Capacity of Parallel IM-DD Optical Wireless Channels

    KAUST Repository

    Chaaban, Anas

    2016-11-29

    The capacity of parallel intensity-modulation and direct-detection (IM-DD) optical wireless channels with total average intensity and per-channel peak intensity constraints is studied. The optimal intensity allocation at low signal-to-noise ratio (SNR) is derived, leading to the capacity-achieving onoff keying (OOK) distribution. Interestingly, while activating the strongest channel is optimal if (i) the peak intensity is fixed, this is not the case if (ii) the peak intensity is proportional to the average intensity. The minimum average optical intensity per bit is also studied, and is characterized for case (i) where it is achievable at low SNR. However, in case (ii), the average optical intensity per bit grows indefinitely as SNR decreases, indicating that lower optical intensity per bit can be achieved at moderate SNR than at low SNR.

  15. Distributed Antenna Channels with Regenerative Relaying: Relay Selection and Asymptotic Capacity

    Directory of Open Access Journals (Sweden)

    Aitor del Coso

    2007-11-01

    Full Text Available Multiple-input-multiple-output (MIMO techniques have been widely proposed as a means to improve capacity and reliability of wireless channels, and have become the most promising technology for next generation networks. However, their practical deployment in current wireless devices is severely affected by antenna correlation, which reduces their impact on performance. One approach to solve this limitation is relaying diversity. In relay channels, a set of N wireless nodes aids a source-destination communication by relaying the source data, thus creating a distributed antenna array with uncorrelated path gains. In this paper, we study this multiple relay channel (MRC following a decode-and-forward (D&F strategy (i.e., regenerative forwarding, and derive its achievable rate under AWGN. A half-duplex constraint on relays is assumed, as well as distributed channel knowledge at both transmitter and receiver sides of the communication. For this channel, we obtain the optimum relay selection algorithm and the optimum power allocation within the network so that the transmission rate is maximized. Likewise, we bound the ergodic performance of the achievable rate and derive its asymptotic behavior in the number of relays. Results show that the achievable rate of regenerative MRC grows as the logarithm of the Lambert W function of the total number of relays, that is, 𝒞=log⁡2(W0(N. Therefore, D&F relaying, cannot achieve the capacity of actual MISO channels.

  16. Estimation of MIMO channel capacity from phase-noise impaired measurements

    DEFF Research Database (Denmark)

    Pedersen, Troels; Yin, Xuefeng; Fleury, Bernard Henri

    2008-01-01

    Due to the significantly reduced cost and effort for system calibration time-division multiplexing (TDM) is a commonly used technique to switch between the transmit and receive antennas in multiple-input multiple-output (MIMO) radio channel sounding. Nonetheless, Baum et al. [1], [2] have shown t...... matrix. It is shown by means of Monte Carlo simulations assuming a measurementbased phase noise model, that the MIMO channel capacity can be estimated accurately for signal to noise ratios up to about 35 dB......Due to the significantly reduced cost and effort for system calibration time-division multiplexing (TDM) is a commonly used technique to switch between the transmit and receive antennas in multiple-input multiple-output (MIMO) radio channel sounding. Nonetheless, Baum et al. [1], [2] have shown...... that phase noise of the transmitter and receiver local oscillators, when it is assumed to be a white Gaussian random process, can cause large errors of the estimated channel capacity of a low-rank MIMO channel when the standard channel matrix estimator is used. Experimental evidence shows that consecutive...

  17. Many-body physics and the capacity of quantum channels with memory

    International Nuclear Information System (INIS)

    Plenio, M B; Virmani, S

    2008-01-01

    In most studies of the capacity of quantum channels, it is assumed that the errors in the use of each channel are independent. However, recent work has begun to investigate the effects of memory or correlations in the error, and has led to suggestions that there can be interesting non-analytic behaviour in the capacity of such channels. In a previous paper, we pursued this issue by connecting the study of channel capacities under correlated error to the study of critical behaviour in many-body physics. This connection enables the use of techniques from many-body physics to either completely solve or understand qualitatively a number of interesting models of correlated error with analogous behaviour to associated many-body systems. However, in order for this approach to work rigorously, there are a number of technical properties that need to be established for the lattice systems being considered. In this paper, we discuss these properties in detail, and establish them for some classes of many-body system

  18. Quantum Enigma Machines and the Locking Capacity of a Quantum Channel

    Directory of Open Access Journals (Sweden)

    Saikat Guha

    2014-01-01

    Full Text Available The locking effect is a phenomenon that is unique to quantum information theory and represents one of the strongest separations between the classical and quantum theories of information. The Fawzi-Hayden-Sen locking protocol harnesses this effect in a cryptographic context, whereby one party can encode n bits into n qubits while using only a constant-size secret key. The encoded message is then secure against any measurement that an eavesdropper could perform in an attempt to recover the message, but the protocol does not necessarily meet the composability requirements needed in quantum key distribution applications. In any case, the locking effect represents an extreme violation of Shannon’s classical theorem, which states that information-theoretic security holds in the classical case if and only if the secret key is the same size as the message. Given this intriguing phenomenon, it is of practical interest to study the effect in the presence of noise, which can occur in the systems of both the legitimate receiver and the eavesdropper. This paper formally defines the locking capacity of a quantum channel as the maximum amount of locked information that can be reliably transmitted to a legitimate receiver by exploiting many independent uses of a quantum channel and an amount of secret key sublinear in the number of channel uses. We provide general operational bounds on the locking capacity in terms of other well-known capacities from quantum Shannon theory. We also study the important case of bosonic channels, finding limitations on these channels’ locking capacity when coherent-state encodings are employed and particular locking protocols for these channels that might be physically implementable.

  19. Digital non-linear equalization for flexible capacity ultradense WDM channels for metro core networking

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Zhang, Xu; Larsen, Knud J.

    2011-01-01

    carriers, we demonstrate that a digital non-linear equalization allow to mitigate inter-channel interference and improve overall system performance in terms of OSNR. Evaluation of the algorithm and comparison with an ultradense WDM system with coherent carriers generated from a single laser are also......An experimental demonstration of Ultradense WDM with advanced digital signal processing is presented. The scheme proposed allows the use of independent tunable DFB lasers spaced at 12.5 GHz for ultradense WDM PM-QPSK flexible capacity channels for metro core networking. To allocate extremely closed...

  20. 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.

  1. On the Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels Using OOK Signaling

    Directory of Open Access Journals (Sweden)

    Antonio García-Zambrana

    2010-01-01

    Full Text Available A new upper bound on the capacity of power- and bandwidth-constrained optical wireless links over gamma-gamma atmospheric turbulence channels with intensity modulation and direct detection is derived when on-off keying (OOK formats are used. In this free-space optical (FSO scenario, unlike previous capacity bounds derived from the classic capacity of the well-known additive white Gaussian noise (AWGN channel with uniform input distribution, a new closed-form upper bound on the capacity is found by bounding the mutual information subject to an average optical power constraint and not only to an average electrical power constraint, showing the fact that the input distribution that maximizes the mutual information varies with the turbulence strength and the signal-to-noise ratio (SNR. Additionally, it is shown that an increase of the peak-to-average optical power ratio (PAOPR provides higher capacity values. Simulation results for the mutual information are further demonstrated to confirm the analytical results under several turbulence conditions.

  2. A unified MGF-based capacity analysis of diversity combiners over generalized fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2012-03-01

    Unified exact ergodic capacity results for L-branch coherent diversity combiners including equal-gain combining (EGC) and maximal-ratio combining (MRC) are not known. This paper develops a novel generic framework for the capacity analysis of L-branch EGC/MRC over generalized fading channels. The framework is used to derive new results for the gamma-shadowed generalized Nakagami-m fading model which can be a suitable model for the fading environments encountered by high frequency (60 GHz and above) communications. The mathematical formalism is illustrated with some selected numerical and simulation results confirming the correctness of our newly proposed framework. © 2012 IEEE.

  3. Unconstrained Capacities of Quantum Key Distribution and Entanglement Distillation for Pure-Loss Bosonic Broadcast Channels.

    Science.gov (United States)

    Takeoka, Masahiro; Seshadreesan, Kaushik P; Wilde, Mark M

    2017-10-13

    We consider quantum key distribution (QKD) and entanglement distribution using a single-sender multiple-receiver pure-loss bosonic broadcast channel. We determine the unconstrained capacity region for the distillation of bipartite entanglement and secret key between the sender and each receiver, whenever they are allowed arbitrary public classical communication. A practical implication of our result is that the capacity region demonstrated drastically improves upon rates achievable using a naive time-sharing strategy, which has been employed in previously demonstrated network QKD systems. We show a simple example of a broadcast QKD protocol overcoming the limit of the point-to-point strategy. Our result is thus an important step toward opening a new framework of network channel-based quantum communication technology.

  4. Capacity bounds for the 2-user Gaussian IM-DD optical multiple-access channel

    KAUST Repository

    Al-Ebraheemy, Omer M. S.

    2016-11-01

    Optical wireless communications (OWC) is a potential solution for coping with the mismatch between the users growing demand for higher data-rates and the wireless network capabilities. In this paper, a multi-user OWC scenario is studied from an in formation-theoretic perspective. The studied network consists of two users communicating simultaneously with one access point using OWC, thus establishing an optical uplink channel. The capacity of this network is an important metric which reflects the highest possible communication rates that can be achieved over this channel. Capacity outer and inner bounds are derived, and are shown to be fairly tight in the high signal-to-noise ratio regime. © 2016 IEEE.

  5. Unconstrained Capacities of Quantum Key Distribution and Entanglement Distillation for Pure-Loss Bosonic Broadcast Channels

    Science.gov (United States)

    Takeoka, Masahiro; Seshadreesan, Kaushik P.; Wilde, Mark M.

    2017-10-01

    We consider quantum key distribution (QKD) and entanglement distribution using a single-sender multiple-receiver pure-loss bosonic broadcast channel. We determine the unconstrained capacity region for the distillation of bipartite entanglement and secret key between the sender and each receiver, whenever they are allowed arbitrary public classical communication. A practical implication of our result is that the capacity region demonstrated drastically improves upon rates achievable using a naive time-sharing strategy, which has been employed in previously demonstrated network QKD systems. We show a simple example of a broadcast QKD protocol overcoming the limit of the point-to-point strategy. Our result is thus an important step toward opening a new framework of network channel-based quantum communication technology.

  6. A Unified Simulation Approach for the Fast Outage Capacity Evaluation over Generalized Fading Channels

    KAUST Repository

    Rached, Nadhir B.

    2016-01-06

    The outage capacity (OC) is among the most important performance metrics of communication systems over fading channels. The evaluation of the OC, when equal gain combining (EGC) or maximum ratio combining (MRC) diversity techniques are employed, boils down to computing the cumulative distribution function (CDF) of the sum of channel envelopes (equivalently amplitudes) for EGC or channel gains (equivalently squared enveloped/ amplitudes) for MRC. Closed-form expressions of the CDF of the sum of many generalized fading variates are generally unknown and constitute open problems. We develop a unified hazard rate twisting Importance Sampling (IS) based approach to efficiently estimate the CDF of the sum of independent arbitrary variates. The proposed IS estimator is shown to achieve an asymptotic optimality criterion, which clearly guarantees its efficiency. Some selected simulation results are also shown to illustrate the substantial computational gain achieved by the proposed IS scheme over crude Monte Carlo simulations.

  7. 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.

  8. A unified simulation approach for the fast outage capacity evaluation over generalized fading channels

    KAUST Repository

    Rached, Nadhir B.

    2015-06-14

    The outage capacity (OC) is among the most important performance metrics of communication systems over fading channels. The evaluation of the OC, when Equal Gain Combining (EGC) or Maximum Ratio Combining (MRC) diversity techniques are employed, boils down to computing the Cumulative Distribution Function (CDF) of the sum of channel envelopes (equivalently amplitudes) for EGC or channel gain (equivalently squared enveloped/amplitudes) for MRC. Closed-form expressions of the CDF of the sum of many generalized fading variates are generally unknown and constitute open problems. In this paper, we develop a unified hazard rate twisting Importance Sampling (IS) based approach to efficiently estimate the CDF of the sum of independent arbitrary variates. The proposed IS estimator is shown to achieve an asymptotic optimality criterion, which clearly guarantees its efficiency. Some selected simulation results are also shown to illustrate the substantial computational gain achieved by the proposed IS scheme over crude Monte-Carlo simulations.

  9. Capacity Bounds for the Gaussian IM-DD Optical Multiple-Access Channel

    KAUST Repository

    Chaaban, Anas; Al-Ebraheemy, Omer M. S.; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2017-01-01

    Optical wireless communications (OWC) is a promising technology for closing the mismatch between the growing number of connected devices and the limited wireless network capabilities. Similar to downlink, uplink can also benefit from OWC for establishing connectivity between such devices and an optical access point. In this context, the incoherent intensitymodulation and direct-detection (IM-DD) scheme is desirable in practice. Hence, it is important to understand the fundamental limits of communication rates over an OWC uplink employing IM-DD, i.e., the channel capacity. This uplink, modeled as a Gaussian multiple-access channel (MAC) for indoors OWC, is studied in this paper, under the IM-DD constraints which form the main difference with the standard Gaussian MAC commonly studied in the radio-frequency context. Capacity region outer and inner bounds for this channel are derived. The bounds are fairly close at high signal-to-noise ratio (SNR), where a truncated- Gaussian input distribution achieves the capacity region within a constant gap. Furthermore, the bounds coincide at low SNR showing the optimality of on-off keying combined with successive cancellation decoding in this regime. At moderate SNR, an optimized uniformly-spaced discrete input distribution achieves fairly good performance.

  10. Capacity limits of spectrum-sharing systems over hyper-fading channels

    KAUST Repository

    Ekin, Sabit

    2011-01-20

    Cognitive radio (CR) with spectrum-sharing feature is a promising technique to address the spectrum under-utilization problem in dynamically changing environments. In this paper, the achievable capacity gain of spectrum-sharing systems over dynamic fading environments is studied. To perform a general analysis, a theoretical fading model called hyper-fading model that is suitable to the dynamic nature of CR channel is proposed. Closed-form expressions of probability density function (PDF) and cumulative density function (CDF) of the signal-to-noise ratio (SNR) for secondary users (SUs) in spectrum-sharing systems are derived. In addition, the capacity gains achievable with spectrum-sharing systems in high and low power regions are obtained. The effects of different fading figures, average fading powers, interference temperatures, peak powers of secondary transmitters, and numbers of SUs on the achievable capacity are investigated. The analytical and simulation results show that the fading figure of the channel between SUs and primary base-station (PBS), which describes the diversity of the channel, does not contribute significantly to the system performance gain. © 2011 John Wiley & Sons, Ltd.

  11. Capacity Bounds for the Gaussian IM-DD Optical Multiple-Access Channel

    KAUST Repository

    Chaaban, Anas

    2017-03-18

    Optical wireless communications (OWC) is a promising technology for closing the mismatch between the growing number of connected devices and the limited wireless network capabilities. Similar to downlink, uplink can also benefit from OWC for establishing connectivity between such devices and an optical access point. In this context, the incoherent intensitymodulation and direct-detection (IM-DD) scheme is desirable in practice. Hence, it is important to understand the fundamental limits of communication rates over an OWC uplink employing IM-DD, i.e., the channel capacity. This uplink, modeled as a Gaussian multiple-access channel (MAC) for indoors OWC, is studied in this paper, under the IM-DD constraints which form the main difference with the standard Gaussian MAC commonly studied in the radio-frequency context. Capacity region outer and inner bounds for this channel are derived. The bounds are fairly close at high signal-to-noise ratio (SNR), where a truncated- Gaussian input distribution achieves the capacity region within a constant gap. Furthermore, the bounds coincide at low SNR showing the optimality of on-off keying combined with successive cancellation decoding in this regime. At moderate SNR, an optimized uniformly-spaced discrete input distribution achieves fairly good performance.

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

    KAUST Repository

    Rezki, Zouheir; Alouini, Mohamed-Slim

    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 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.

  13. 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.

  14. Capacity limits of spectrum-sharing systems over hyper-fading channels

    KAUST Repository

    Ekin, Sabit; Yilmaz, Ferkan; Ç elebi, Hasari Burak; Qaraqe, Khalid A.; Alouini, Mohamed-Slim; Serpedin, Erchin

    2011-01-01

    Cognitive radio (CR) with spectrum-sharing feature is a promising technique to address the spectrum under-utilization problem in dynamically changing environments. In this paper, the achievable capacity gain of spectrum-sharing systems over dynamic fading environments is studied. To perform a general analysis, a theoretical fading model called hyper-fading model that is suitable to the dynamic nature of CR channel is proposed. Closed-form expressions of probability density function (PDF) and cumulative density function (CDF) of the signal-to-noise ratio (SNR) for secondary users (SUs) in spectrum-sharing systems are derived. In addition, the capacity gains achievable with spectrum-sharing systems in high and low power regions are obtained. The effects of different fading figures, average fading powers, interference temperatures, peak powers of secondary transmitters, and numbers of SUs on the achievable capacity are investigated. The analytical and simulation results show that the fading figure of the channel between SUs and primary base-station (PBS), which describes the diversity of the channel, does not contribute significantly to the system performance gain. © 2011 John Wiley & Sons, Ltd.

  15. A Novel Through Capacity Model for One-way Channel Based on Characteristics of the Vessel Traffic Flow

    Directory of Open Access Journals (Sweden)

    Yuanyuan Nie

    2017-09-01

    Full Text Available Vessel traffic flow is a key parameter for channel-through capacity and is of great significance to vessel traffic management, channel and port design and navigational risk evaluation. Based on the study of parameters of characteristics of vessel traffic flow related to channel-through capacity, this paper puts forward a brand-new mathematical model for one-way channel-through capacity in which parameters of channel length, vessel arrival rate and velocity difference in different vessels are involved and a theoretical calculating mechanism for the channel-through capacity is provided. In order to verify availability and reliability of the model, extensive simulation studies have been carried out and based on the historical AIS data, an analytical case study on the Xiazhimen Channel validating the proposed model is presented. Both simulation studies and the case study show that the proposed model is valid and all relative parameters can be readjusted and optimized to further improve the channel-through capacity. Thus, all studies demonstrate that the model is valuable for channel design and vessel management.

  16. On the Ergodic Capacity of Dual-Branch Correlated Log-Normal Fading Channels with Applications

    KAUST Repository

    Al-Quwaiee, Hessa

    2015-05-01

    Closed-form expressions of the ergodic capacity of independent or correlated diversity branches over Log-Normal fading channels are not available in the literature. Thus, it is become of an interest to investigate the behavior of such metric at high signal-to-noise (SNR). In this work, we propose simple closed-form asymptotic expressions of the ergodic capacity of dual-branch correlated Log- Normal corresponding to selection combining, and switch-and-stay combining. Furthermore, we capitalize on these new results to find new asymptotic ergodic capacity of correlated dual- branch free-space optical communication system under the impact of pointing error with both heterodyne and intensity modulation/direct detection. © 2015 IEEE.

  17. Achievable capacity of a spectrum sharing system over hyper fading channels

    KAUST Repository

    Ekin, Sabit

    2009-11-01

    Cognitive radio with spectrum sharing feature is a promising technique to address the spectrum under-utilization problem in dynamically changing environments. In this paper, achievable capacity gain of spectrum sharing systems over dynamic fading environments is studied. For the analysis, a theoretical fading model called hyper fading model that is suitable to the dynamic nature of cognitive radio channel is proposed. Closed-form expression of probability density function (PDF) and cumulative density function (CDF) of the signal-to-noise ratio (SNR) for secondary users in spectrum sharing systems are derived. In addition, the capacity gains achievable with spectrum sharing systems in high and low power regions are obtained. Numerical simulations are performed to study the effects of different fading figures, average powers, interference temperature, and number of secondary users on the achievable capacity.

  18. Functional connectivity among multi-channel EEGs when working memory load reaches the capacity.

    Science.gov (United States)

    Zhang, Dan; Zhao, Huipo; Bai, Wenwen; Tian, Xin

    2016-01-15

    Evidence from behavioral studies has suggested a capacity existed in working memory. As the concept of functional connectivity has been introduced into neuroscience research in the recent years, the aim of this study is to investigate the functional connectivity in the brain when working memory load reaches the capacity. 32-channel electroencephalographs (EEGs) were recorded for 16 healthy subjects, while they performed a visual working memory task with load 1-6. Individual working memory capacity was calculated according to behavioral results. Short-time Fourier transform was used to determine the principal frequency band (theta band) related to working memory. The functional connectivity among EEGs was measured by the directed transform function (DTF) via spectral Granger causal analysis. The capacity was 4 calculated from the behavioral results. The power was focused in the frontal midline region. The strongest connectivity strengths of EEG theta components from load 1 to 6 distributed in the frontal midline region. The curve of DTF values vs load numbers showed that DTF increased from load 1 to 4, peaked at load 4, then decreased after load 4. This study finds that the functional connectivity between EEGs, described quantitatively by DTF, became less strong when working memory load exceeded the capacity. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Meandered Monopoles for 700 MHz LTE Handsets and Improved MIMO Channel Capacity Performance

    Directory of Open Access Journals (Sweden)

    I. Dioum

    2011-12-01

    Full Text Available In this paper, we present the design and the measurement of MIMO meandered monopole antennas and the computation of their channel capacity performance. The initial proposed handset-system is composed of a meandered monopole operating in the LTE 700 MHz band, connected to a parasitic radiating element for the upper 2.5 GHz LTE band. Two antennas of the same kind are then closely positioned on the same 120x50 mm2 Printed Circuit Board (PCB. A neutralization line connects the two antennas to enhance their port-to-port isolation in the 700 MHz band. The computation of the channel capacity performance in this band is based on propagation simulations performed with the GRIMM model from the CREMANT. Two system-prototypes are evaluated: one with the neutralization line for enhanced port-to-port isolation and a second without the neutralization exhibiting poor antenna-to-antenna isolation. It is demonstrated that the neutralization technique helps in giving a minimum improvement of 12% of the capacity performance of the handset-system, and a maximum improvement 46%, in the chosen environment.

  20. Capacity of the inflow river channels of the Krpelany and Hricov reservoirs with respect to flood control

    International Nuclear Information System (INIS)

    Capekova, Z.

    2004-01-01

    In this presentation author deals with the capacity of the inflow river channels of the Krpelany and Hricov reservoirs with respect to flood control (Vah River, Orava River, Kysuce River and Rajcianka River, Slovakia)

  1. A novel ergodic capacity analysis of diversity combining and multihop transmission systems over generalized composite fading channels

    KAUST Repository

    Yilmaz, Ferkan; Alouini, Mohamed-Slim

    2012-01-01

    Ergodic capacity is an important performance measure associated with reliable communication at the highest rate at which information can be sent over the channel with a negligible probability of error. In the shadow of this definition, diversity

  2. An Isomorphism between Lyapunov Exponents and Shannon's Channel Capacity

    Energy Technology Data Exchange (ETDEWEB)

    Friedland, Gerald [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Metere, Alfredo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-06-07

    We demonstrate that discrete Lyapunov exponents are isomorphic to numeric overflows of the capacity of an arbitrary noiseless and memoryless channel in a Shannon communication model with feedback. The isomorphism allows the understanding of Lyapunov exponents in terms of Information Theory, rather than the traditional definitions in chaos theory. The result also implies alternative approaches to the calculation of related quantities, such as the Kolmogorov Sinai entropy which has been linked to thermodynamic entropy. This work provides a bridge between fundamental physics and information theory. It suggests, among other things, that machine learning and other information theory methods can be employed at the core of physics simulations.

  3. Outage and Capacity Performance Evaluation of Distributed MIMO Systems over a Composite Fading Channel

    Directory of Open Access Journals (Sweden)

    Wenjie Peng

    2014-01-01

    Full Text Available The exact closed-form expressions regarding the outage probability and capacity of distributed MIMO (DMIMO systems over a composite fading channel are derived. This is achieved firstly by using a lognormal approximation to a gamma-lognormal distribution when a mobile station (MS in the cell is in a fixed position, and the so-called maximum ratio transmission/selected combining (MRT-SC and selected transmission/maximum ratio combining (ST-MRC schemes are adopted in uplink and downlink, respectively. Then, based on a newly proposed nonuniform MS cell distribution model, which is more consistent with the MS cell hotspot distribution in an actual communication environment, the average outage probability and capacity formulas are further derived. Finally, the accuracy of the approximation method and the rationality of the corresponding theoretical analysis regarding the system performance are proven and illustrated by computer simulations.

  4. On the Capacity Region of the Intensity-Modulation Direct-Detection Optical Broadcast Channel

    KAUST Repository

    Chaaban, Anas

    2015-08-11

    The capacity of the intensity-modulation direct-detection free-space optical broadcast channel (OBC) is investigated. The Gaussian model with input-independent Gaussian noise is used, with both average and peak intensity constraints. An outer bound on the capacity region is derived by adapting Bergmans\\' approach to the OBC. Inner bounds are derived by using superposition coding with either truncated-Gaussian distributions or discrete distributions. While the discrete input distribution achieves higher rates than the truncated-Gaussian distribution, the latter allows expressing the achievable rate region in a closed form. At high signal-to-noise ratio (SNR), it is shown that the truncated-Gaussian distribution is nearly optimal. It achieves the symmetric-capacity within a constant gap (independent of SNR), which approaches half a bit as the number of users grows large. It also achieves the capacity region within a constant gap, which depends on the number of users. At low SNR, it is shown that on-off keying with time-division multiple-access (TDMA) is optimal, as it achieves any point on the boundary of the developed outer bound. This is interesting in practice since both OOK and TDMA have low complexity. At moderate SNR (typically [0,8] dB), a discrete distribution with a small alphabet size achieves a fairly good performance in terms of symmetric rate.

  5. On the Capacity of the Intensity-Modulation Direct-Detection Optical Broadcast Channel

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2016-01-01

    The capacity of the intensity-modulation directdetection optical broadcast channel (OBC) is investigated, under both average and peak intensity constraints. An outer bound on the capacity region is derived by adapting Bergmans’ approach to the OBC. Inner bounds are derived by using superposition coding with either truncated-Gaussian (TG) distributions or discrete distributions. While the discrete distribution achieves higher rates, the TG distribution leads to a simpler representation of the achievable rate region. At high signal-to-noise ratio (SNR), it is shown that the TG distribution is nearly optimal. It achieves the symmetric-capacity within a constant gap (independent of SNR), which approaches half a bit as the number of users grows. It also achieves the capacity region within a constant gap. At low SNR, it is shown that on-off keying (OOK) with time-division multipleaccess (TDMA) is optimal. This is interesting in practice since both OOK and TDMA have low complexity. At moderate SNR (typically [0,8] dB), a discrete distribution with a small alphabet size achieves fairly good performance.

  6. On the Capacity of the Intensity-Modulation Direct-Detection Optical Broadcast Channel

    KAUST Repository

    Chaaban, Anas

    2016-01-12

    The capacity of the intensity-modulation directdetection optical broadcast channel (OBC) is investigated, under both average and peak intensity constraints. An outer bound on the capacity region is derived by adapting Bergmans’ approach to the OBC. Inner bounds are derived by using superposition coding with either truncated-Gaussian (TG) distributions or discrete distributions. While the discrete distribution achieves higher rates, the TG distribution leads to a simpler representation of the achievable rate region. At high signal-to-noise ratio (SNR), it is shown that the TG distribution is nearly optimal. It achieves the symmetric-capacity within a constant gap (independent of SNR), which approaches half a bit as the number of users grows. It also achieves the capacity region within a constant gap. At low SNR, it is shown that on-off keying (OOK) with time-division multipleaccess (TDMA) is optimal. This is interesting in practice since both OOK and TDMA have low complexity. At moderate SNR (typically [0,8] dB), a discrete distribution with a small alphabet size achieves fairly good performance.

  7. On the Capacity of the 2-User IM-DD Optical Broadcast Channel

    KAUST Repository

    Chaaban, Anas

    2016-02-26

    The capacity of the intensity-modulation directdetection (IM-DD) optical broadcast channel (OBC) is investigated. The OBC is modeled as a Gaussian channel with input-independent noise and both average and peak input constraints. Outer and inner bounds on the capacity region are derived. The outer bounds are based on Bergmans\\' approach. The inner bounds are based on superposition coding with either truncated-Gaussian or discrete input distributions. By comparing the bounds, we observe that the truncated- Gaussian distribution is nearly optimal at high signal-to-noise ratio (SNR). At low SNR on the other hand, on-off keying (OOK) combined with time-division multiple-access (TDMA) is optimal; it achieves any point on the boundary of the developed outer bound. This is interesting in practice since both OOK and TDMA have low complexity. At moderate SNR (typically [0; 8] dB), a discrete input distribution with a small alphabet size achieves a fairly good performance. © 2015 IEEE.

  8. A Methodology for Measuring Voice Quality Using PESQ and Interactive Voice Response in the GSM Channel Designed by OpenBTS

    Directory of Open Access Journals (Sweden)

    Pavol Partila

    2013-01-01

    Full Text Available This article discusses a methodology for rating the quality of mobile calls. Majority telecommunications service from the perspective of the whole world is using mobile telephony networks. One of the problems affecting this service and its quality are landscape barriers, which prevent the spread signal. Price and complex construction of classic BTS does not allow their dense distribution. In such cases, one solution is to use OpenBTS technology. Design of OpenBTS is more available, so it can be applied to much more places and more complex points. Purpose of this measurement is a model for effective stations deployment, due to shape and distribution of local barriers that reduce signal power, and thus the quality of speech. GSM access point for our mobile terminals is OpenBTS USRP N210 station. The PESQ method for evaluating of speech quality is compared with the subjective evaluation, which provides Asterisk PBX with IVR call back. Measurement method was taken into account the call quality depending on terminal position. The measured results and its processing bring knowledge to use this technology for more complicated locations with degraded signal level and increases the quality of voice services in telecommunications.

  9. Construction and Capacity Analysis of High-Rank LoS MIMO Channels in High Speed Railway Scenarios

    Directory of Open Access Journals (Sweden)

    Jingya Yang

    2012-01-01

    Full Text Available The validity of the maximum capacity criterion applied to realize high-rank line-of-sight (LoS multiple-input multiple-output (MIMO channels is investigated for high speed railway scenarios. Performance is evaluated by ergodic capacity. Numerical results demonstrate that by simply adjusting antenna spacing according to the maximum capacity criterion, significant capacity gains are achievable. We find relatively low sensitivity of the system to displacements from the optimal point and angle in relatively short range. Thus, we present two proposals to reconfigure antenna arrays so as to maximize LoS MIMO capacity in the high speed railway scenarios

  10. Approaching the MIMO Capacity with a Low-Rate Feedback Channel in V-BLAST

    Directory of Open Access Journals (Sweden)

    Lozano Angel

    2004-01-01

    Full Text Available This paper presents an extension of the vertical Bell Laboratories Layered Space-Time (V-BLAST architecture in which the closed-loop multiple-input multiple-output (MIMO capacity can be approached with conventional scalar coding, optimum successive decoding (OSD, and independent rate assignments for each transmit antenna. This theoretical framework is used as a basis for the proposed algorithms whereby rate and power information for each transmit antenna is acquired via a low-rate feedback channel. We propose the successive quantization with power control (SQPC and successive rate and power quantization (SRPQ algorithms. In SQPC, rate quantization is performed with continuous power control. This performs better than simply quantizing the rates without power control. A more practical implementation of SQPC is SRPQ, in which both rate and power levels are quantized. The performance loss due to power quantization is insignificant when 4–5 bits are used per antenna. Both SQPC and SRPQ show an average total rate close to the closed-loop MIMO capacity if a capacity-approaching scalar code is used per antenna.

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

    KAUST Repository

    Rezki, Zouheir; Alouini, Mohamed-Slim

    2014-01-01

    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

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

    KAUST Repository

    Rezki, Zouheir; Alouini, Mohamed-Slim

    2013-01-01

    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

  13. Sediment Transport Capacity and Channel Processes in a Humid Tropical Montane River - Rio Pacuare, Costa Rica

    Science.gov (United States)

    Lind, P.; McDowell, P. F.

    2017-12-01

    Investigating sediment transport capacity as well as the spatial and temporal variations of sediment flux are critical component of river research, especially for applications in resource management and conservation, hazards assessment and planning, and riverine ecology. The bedload fraction of sediment transported through montane rivers often defines channel and bed form processes. It is understood that humid tropical montane rivers are capable of producing some of the largest quantities of sediment per unit drainage area. Bedload flux reported on a few Southeast Asian humid tropical montane rivers show that bedload constituted 16-75% of the total sediment load - this is notably higher than the generally accepted 10% of a channel's sediment load. However, to date almost all of the research done on sediment transport in humid tropical systems has focused on suspended load. This study presents annual bedload transport rate estimates for six field sites distributed within 45 river kilometers (Rkm) of the montane portion of the Rio Pacuare, located in the Talamanca Mountains of Costa Rica. This research reveals that flows capable of mobilizing the D84 occur on average at least once but often multiple times a year in this river system. The Rio Pacuare has a sufficient supply of sediment to meet its high transport capacity needs. As a result, large active bars composed of imbricated boulders define channel form at moderate and low flows throughout the study area. Differences in the magnitude, as well as the spatial and temporal variations of sediment flux at each field site are discussed in relation to stream power, and annual/inter-annual precipitation patterns. A unique mix of field and remote sensing techniques were applied to address these questions and to overcome some of the challenges of tropical river research. For example, due to the large grain size and high stream energy, grain mobilization and validation of modeled shear stress requirements for transport

  14. Low SNR capacity for MIMO Rician and Rayleigh-product fading channels with single co-channel interferer and noise

    KAUST Repository

    Zhong, Caijun; Jin, Shi; Wong, Kaikit; Alouini, Mohamed-Slim; Ratnarajah, Tharm

    2010-01-01

    . Exact analytical expressions for the minimum energy per information bit, {Eb/N0min, and wideband slope, S0, are derived for both channels. Our results show that the minimum energy per information bit is the same for both channels while their wideband

  15. Unified Importance Sampling Schemes for Efficient Simulation of Outage Capacity over Generalized Fading Channels

    KAUST Repository

    Rached, Nadhir B.; Kammoun, Abla; Alouini, Mohamed-Slim; Tempone, Raul

    2015-01-01

    The outage capacity (OC) is among the most important performance metrics of communication systems operating over fading channels. Of interest in the present paper is the evaluation of the OC at the output of the Equal Gain Combining (EGC) and the Maximum Ratio Combining (MRC) receivers. In this case, it can be seen that this problem turns out to be that of computing the Cumulative Distribution Function (CDF) for the sum of independent random variables. Since finding a closedform expression for the CDF of the sum distribution is out of reach for a wide class of commonly used distributions, methods based on Monte Carlo (MC) simulations take pride of price. In order to allow for the estimation of the operating range of small outage probabilities, it is of paramount importance to develop fast and efficient estimation methods as naive Monte Carlo (MC) simulations would require high computational complexity. In this line, we propose in this work two unified, yet efficient, hazard rate twisting Importance Sampling (IS) based approaches that efficiently estimate the OC of MRC or EGC diversity techniques over generalized independent fading channels. The first estimator is shown to possess the asymptotic optimality criterion and applies for arbitrary fading models, whereas the second one achieves the well-desired bounded relative error property for the majority of the well-known fading variates. Moreover, the second estimator is shown to achieve the asymptotic optimality property under the particular Log-normal environment. Some selected simulation results are finally provided in order to illustrate the substantial computational gain achieved by the proposed IS schemes over naive MC simulations.

  16. Unified Importance Sampling Schemes for Efficient Simulation of Outage Capacity over Generalized Fading Channels

    KAUST Repository

    Rached, Nadhir B.

    2015-11-13

    The outage capacity (OC) is among the most important performance metrics of communication systems operating over fading channels. Of interest in the present paper is the evaluation of the OC at the output of the Equal Gain Combining (EGC) and the Maximum Ratio Combining (MRC) receivers. In this case, it can be seen that this problem turns out to be that of computing the Cumulative Distribution Function (CDF) for the sum of independent random variables. Since finding a closedform expression for the CDF of the sum distribution is out of reach for a wide class of commonly used distributions, methods based on Monte Carlo (MC) simulations take pride of price. In order to allow for the estimation of the operating range of small outage probabilities, it is of paramount importance to develop fast and efficient estimation methods as naive Monte Carlo (MC) simulations would require high computational complexity. In this line, we propose in this work two unified, yet efficient, hazard rate twisting Importance Sampling (IS) based approaches that efficiently estimate the OC of MRC or EGC diversity techniques over generalized independent fading channels. The first estimator is shown to possess the asymptotic optimality criterion and applies for arbitrary fading models, whereas the second one achieves the well-desired bounded relative error property for the majority of the well-known fading variates. Moreover, the second estimator is shown to achieve the asymptotic optimality property under the particular Log-normal environment. Some selected simulation results are finally provided in order to illustrate the substantial computational gain achieved by the proposed IS schemes over naive MC simulations.

  17. On the computation of the higher order statistics of the channel capacity for amplify-and-forward multihop transmission

    KAUST Repository

    Yilmaz, Ferkan; Tabassum, Hina; Alouini, Mohamed-Slim

    2014-01-01

    Higher order statistics (HOS) of the channel capacity provide useful information regarding the level of reliability of signal transmission at a particular rate. In this paper, we propose a novel and unified analysis, which is based on the moment-generating function (MGF) approach, to efficiently and accurately compute the HOS of the channel capacity for amplify-and-forward (AF) multihop transmission over generalized fading channels. More precisely, our easy-to-use and tractable mathematical formalism requires only the reciprocal MGFs of the transmission hop signal-to-noise ratio (SNR). Numerical and simulation results, which are performed to exemplify the usefulness of the proposed MGF-based analysis, are shown to be in perfect agreement. © 2013 IEEE.

  18. An Orbital Angular Momentum (OAM) Mode Reconfigurable Antenna for Channel Capacity Improvement and Digital Data Encoding.

    Science.gov (United States)

    Liu, Baiyang; Lin, Guoying; Cui, Yuehui; Li, RongLin

    2017-08-29

    For purpose of utilizing orbital angular momentum (OAM) mode diversity, multiple OAM beams should be generated preferably by a single antenna. In this paper, an OAM mode reconfigurable antenna is proposed. Different from the existed OAM antennas with multiple ports for multiple OAM modes transmitting, the proposed antenna with only a single port, but it can be used to transmit mode 1 or mode -1 OAM beams arbitrary by controlling the PIN diodes on the feeding network through a programmable microcontroller which control by a remote controller. Simulation and measurement results such as return loss, near-field and far-field radiation patterns of two operating states for mode 1 and mode -1, and OAM mode orthogonality are given. The proposed antenna can serve as a candidate for utilizing OAM diversity, namely phase diversity to increase channel capacity at 2.4 GHz. Moreover, an OAM-mode based encoding method is experimentally carried out by the proposed OAM mode reconfigurable antenna, the digital data are encoded and decoded by different OAM modes. At the transmitter, the proposed OAM mode reconfigurable antenna is used to encode the digital data, data symbol 0 and 1 are mapped to OAM mode 1 and mode -1, respectively. At the receiver, the data symbols are decoded by phase gradient method.

  19. A novel ergodic capacity analysis of diversity combining and multihop transmission systems over generalized composite fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2012-06-01

    Ergodic capacity is an important performance measure associated with reliable communication at the highest rate at which information can be sent over the channel with a negligible probability of error. In the shadow of this definition, diversity receivers (such as selection combining, equal-gain combining and maximal-ratio combining) and transmission techniques (such as cascaded fading channels, amplify-and-forward multihop transmission) are deployed in mitigating various performance impairing effects such as fading and shadowing in digital radio communication links. However, the exact analysis of ergodic capacity is in general not always possible for all of these forms of diversity receivers and transmission techniques over generalized composite fading environments due to it\\'s mathematical intractability. In the literature, published papers concerning the exact analysis of ergodic capacity have been therefore scarce (i.e., only [1] and [2]) when compared to those concerning the exact analysis of average symbol error probability. In addition, they are essentially targeting to the ergodic capacity of the maximal ratio combining diversity receivers and are not readily applicable to the capacity analysis of the other diversity combiners / transmission techniques. In this paper, we propose a novel moment generating function-based approach for the exact ergodic capacity analysis of both diversity receivers and transmission techniques over generalized composite fading environments. As such, we demonstrate how to simultaneously treat the ergodic capacity analysis of all forms of both diversity receivers and multihop transmission techniques. © 2012 IEEE.

  20. Transmission of Voice Signal: BER Performance Analysis of Different FEC Schemes Based OFDM System over Various Channels

    OpenAIRE

    Rashed, Md. Golam; Kabir, M. Hasnat; Reza, Md. Selim; Islam, Md. Matiqul; Shams, Rifat Ara; Masum, Saleh; Ullah, Sheikh Enayet

    2012-01-01

    In this paper, we investigate the impact of Forward Error Correction (FEC) codes namely Cyclic Redundancy Code and Convolution Code on the performance of OFDM wireless communication system for speech signal transmission over both AWGN and fading (Rayleigh and Rician) channels in term of Bit Error Probability. The simulation has been done in conjunction with QPSK digital modulation and compared with uncoded resultstal modulation. In the fading channels, it is found via computer simulation that...

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

    KAUST Repository

    Benkhelifa, Fatma; Rezki, Zouheir; Alouini, Mohamed-Slim

    2013-01-01

    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

  2. Closed-form Capacity Expressions for the α-μ Fading Channel with SC Diversity under Different Adaptive Transmission Strategies

    Science.gov (United States)

    Mohamed, Refaat; Ismail, Mahmoud H.; Newagy, Fatma; Mourad, Heba M.

    2013-03-01

    Stemming from the fact that the α-μ fading distribution is one of the very general fading models used in the literature to describe the small scale fading phenomenon, in this paper, closed-form expressions for the Shannon capacity of the α-μ fading channel operating under four main adaptive transmission strategies are derived assuming integer values for μ. These expressions are derived for the case of no diversity as well as for selection combining diversity with independent and identically distributed branches. The obtained expressions reduce to those previously derived in the literature for the Weibull as well as the Rayleigh fading cases, which are both special cases of the α-μ channel. Numerical results are presented for the capacity under the four adaptive transmission strategies and the effect of the fading parameter as well as the number of diversity branches is studied.

  3. Nonadditivity of quantum and classical capacities for entanglement breaking multiple-access channels and the butterfly network

    International Nuclear Information System (INIS)

    Grudka, Andrzej; Horodecki, Pawel

    2010-01-01

    We analyze quantum network primitives which are entanglement breaking. We show superadditivity of quantum and classical capacity regions for quantum multiple-access channels and the quantum butterfly network. Since the effects are especially visible at high noise they suggest that quantum information effects may be particularly helpful in the case of the networks with occasional high noise rates. The present effects provide a qualitative borderline between superadditivities of bipartite and multipartite systems.

  4. A unified MGF-based capacity analysis of diversity combiners over generalized fading channels

    KAUST Repository

    Yilmaz, Ferkan; Alouini, Mohamed-Slim

    2012-01-01

    Unified exact ergodic capacity results for L-branch coherent diversity combiners including equal-gain combining (EGC) and maximal-ratio combining (MRC) are not known. This paper develops a novel generic framework for the capacity analysis of L-branch

  5. Evaluation of PLC Channel Capacity and ABER Performances for OFDM-Based Two-Hop Relaying Transmission

    Directory of Open Access Journals (Sweden)

    Sana Ezzine

    2017-01-01

    Full Text Available Powerline network is recognized as a favorable infrastructure for Smart Grid to transmit information in the network thanks to its broad coverage and low cost deployment. The existing works are trying to improve and adapt transmission techniques to reduce Powerline Communication (PLC channel attenuation and exploit the limited bandwidth to support high data rate over long distances. Two-hop relaying BroadBand PLC (BB-PLC system, in which Orthogonal Frequency Division Multiplexing (OFDM is used, is considered in this paper. We derive and compare the PLC channel capacity and the end-to-end Average BER (ABER for OFDM-based direct link (DL BB-PLC system and for OFDM-based two-hop relaying BB-PLC system for Amplify and Forward (AF and Decode and Forward (DF protocols. We analyze the improvements when we consider the direct link in a cooperative communication when the relay node only transmits the correctly decoded signal. Maximum ratio combining is employed at the destination node to detect the transmitted signal. In addition, in this paper, we highlight the impact of the relay location on the channel capacity and ABER for AF and DF transmission protocols. Moreover, an efficient use of the direct link was also investigated in this paper.

  6. Achievable capacity of a spectrum sharing system over hyper fading channels

    KAUST Repository

    Ekin, Sabit; Yilmaz, Ferkan; Ç elebi, Hasari Burak; Qaraqe, Khalid A.; Alouini, Mohamed-Slim; Serpedin, Erchin

    2009-01-01

    Cognitive radio with spectrum sharing feature is a promising technique to address the spectrum under-utilization problem in dynamically changing environments. In this paper, achievable capacity gain of spectrum sharing systems over dynamic fading

  7. On the Capacity Region of the Intensity-Modulation Direct-Detection Optical Broadcast Channel

    KAUST Repository

    Chaaban, Anas; Rezki, Zouheir; Alouini, Mohamed-Slim

    2015-01-01

    on the capacity region is derived by adapting Bergmans' approach to the OBC. Inner bounds are derived by using superposition coding with either truncated-Gaussian distributions or discrete distributions. While the discrete input distribution achieves higher rates

  8. Channel capacity of TDD-OFDM-MIMO for multiple access points in a wireless single-frequency-network

    DEFF Research Database (Denmark)

    Takatori, Y.; Fitzek, Frank; Tsunekawa, K.

    2005-01-01

    MIMO data transmission scheme, which combines Single-Frequency-Network (SFN) with TDD-OFDM-MIMO applied for wireless LAN networks. In our proposal, we advocate to use SFN for multiple access points (MAP) MIMO data transmission. The goal of this approach is to achieve very high channel capacity in both......The multiple-input-multiple-output (MIMO) technique is the most attractive candidate to improve the spectrum efficiency in the next generation wireless communication systems. However, the efficiency of MIMO techniques reduces in the line of sight (LOS) environments. In this paper, we propose a new...

  9. MIMO channel capacity versus mutual coupling in multi antenna element system

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2004-01-01

    In this paper the influence of mutual coupling on the capacity of a multiple-input multiple-output (MIMO) antenna system is demonstrated. No direct relation between the envelope correlation and the actual location and orientation of the antennas is found. Even though being essential for high MIMO...... capacity, configurations with the lowest envelope correlations are not necessarily the most suitable for a MIMO system. A certain bandwidth is required as well. Three planar inverted F-antennas (PIFA) located on the same 40 mm x 100 mm ground plane. The antennas that haves a resonant frequency of 1.8 GHz...

  10. Bounds on the Capacity of ASK Molecular Communication Channels with ISI

    OpenAIRE

    Ghavami, Siavash; Adve, Raviraj; Lahouti, Farshad

    2015-01-01

    There are now several works on the use of the additive inverse Gaussian noise (AIGN) model for the random transit time in molecular communication~(MC) channels. The randomness invariably causes inter-symbol interference (ISI) in MC, an issue largely ignored or simplified. In this paper we derive an upper bound and two lower bounds for MC based on amplitude shift keying (ASK) in presence of ISI. The Blahut-Arimoto algorithm~(BAA) is modified to find the input distribution of transmitted symbol...

  11. On the outage capacity of the block fading channel at low-power regime

    KAUST Repository

    Rezki, Zouheir

    2014-06-01

    Outage performance of the M-block fading with additive white Gaussian noise (BF-AWGN) is investigated at low-power regime. We consider delay-constrained constant-rate communications with perfect channel state information (CSI) at both the transmitter and the receiver (CSI-TR), under a short-term power constraint. We show that selection diversity that allocates all the power to the strongest block is asymptotically optimal. Then, we provide a simple characterization of the outage probability in the regime of interest. We quantify the reward due to CSI-TR over the constant-rate constant-power scheme and show that this reward increases with the delay constraint. For instance, for Rayleigh fading, we find that a power gain up to 4.3 dB is achievable. © 2014 IEEE.

  12. Voiced Excitations

    National Research Council Canada - National Science Library

    Holzricher, John

    2004-01-01

    To more easily obtain a voiced excitation function for speech characterization, measurements of skin motion, tracheal tube, and vocal fold, motions were made and compared to EM sensor-glottal derived...

  13. Channel Models for Capacity Evaluation of MIMO Handsets in Data Mode

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ødum; Yanakiev, Boyan; Barrio, Samantha Caporal Del

    2017-01-01

    This work investigates different correlation based models useful for evaluation of outage capacity (OC) of mobile multiple-input multiple-output (MIMO) handsets. The work is based on a large measurement campaign in a micro-cellular setup involving two dual-band base stations, 10 different handsets...... in an indoor environment for different use cases and test users. Several models are evaluated statistically, comparing the OC values estimated from the model and measurement data, respectively, for about 2,700 measurement routes. The models are based on either estimates of the full correlation matrices...... or simplifications. Among other results, it is shown that the OC can be predicted accurately (median error typically within 2.6%) with a model assuming knowledge only of the Tx-correlation coefficient and the mean power gain....

  14. Estimation of Outage Capacity for Free Space Optical Links Over I-K and K Turbulent Channels

    Directory of Open Access Journals (Sweden)

    D. Marinos

    2011-06-01

    Full Text Available The free space optical communication systems are attracting great research and commercial interest due to their capability of transferring data, over short distances, with high rate and security, low cost demands and without licensing fees. However, their performance depends strongly on the atmospheric conditions in the link’s area. In this work, we investigate the influence of the turbulence on the outage capacity of such a system for weak to strong turbulence channels modeled by the I-K and the K-distribution and we derive closed-form expressions for its estimation. Finally, using these expressions we present numerical results for various link cases with different turbulence conditions.

  15. A novel unified expression for the capacity and bit error probability of wireless communication systems over generalized fading channels

    KAUST Repository

    Yilmaz, Ferkan

    2012-07-01

    Analysis of the average binary error probabilities (ABEP) and average capacity (AC) of wireless communications systems over generalized fading channels have been considered separately in past years. This paper introduces a novel moment generating function (MGF)-based unified expression for the ABEP and AC of single and multiple link communications with maximal ratio combining. In addition, this paper proposes the hyper-Fox\\'s H fading model as a unified fading distribution of a majority of the well-known generalized fading environments. As such, the authors offer a generic unified performance expression that can be easily calculated, and that is applicable to a wide variety of fading scenarios. The mathematical formulism is illustrated with some selected numerical examples that validate the correctness of the authors\\' newly derived results. © 1972-2012 IEEE.

  16. Analog voicing detector responds to pitch

    Science.gov (United States)

    Abel, R. S.; Watkins, H. E.

    1967-01-01

    Modified electronic voice encoder /Vocoder/ includes an independent analog mode of operation in addition to the conventional digital mode. The Vocoder is a bandwidth compression equipment that permits voice transmission over channels, having only a fraction of the bandwidth required for conventional telephone-quality speech transmission.

  17. Capacity Enhancement of Uni‐directional In‐band Full‐Duplex Cellular Networks through Co‐channel Interference Cancellation

    Directory of Open Access Journals (Sweden)

    Hyungsik Ju

    2018-03-01

    Full Text Available As implementation of the in‐band full duplex (IFD transceiver becomes feasible, research interest is growing with respect to using IFD communication with cellular networks. However, the cellular network in which the IFD communication is applied inevitably suffers from an increase of the co‐channel interference (CCI due to IFD simultaneous transmission and reception. In this paper, we analyze the performance of a cellular network based on uni‐directional IFD (UD‐IFD communication, wherein an IFD base station simultaneously supports downlink and uplink transmissions of half‐duplex (HD users. In addition, a multi‐pair CCI cancellation (MP‐CCIC method combining CCIC and user pairing is proposed to improve the performance of the UD‐IFD network. Simulation results showed that, compared to a conventional HD cellular network without using CCIC, capacity gain was not obtained in the UD‐IFD cellular network. On the other hand, when applying the proposed MP‐CCIC, the capacity of the UD‐IFD cellular network greatly improved compared to that of an HD cellular network.

  18. Ergodic channel capacity of spatial correlated multiple-input multiple-output free space optical links using multipulse pulse-position modulation

    Science.gov (United States)

    Wang, Huiqin; Wang, Xue; Cao, Minghua

    2017-02-01

    The spatial correlation extensively exists in the multiple-input multiple-output (MIMO) free space optical (FSO) communication systems due to the channel fading and the antenna space limitation. Wilkinson's method was utilized to investigate the impact of spatial correlation on the MIMO FSO communication system employing multipulse pulse-position modulation. Simulation results show that the existence of spatial correlation reduces the ergodic channel capacity, and the reception diversity is more competent to resist this kind of performance degradation.

  19. Tips for Healthy Voices

    Science.gov (United States)

    ... prevent voice problems and maintain a healthy voice: Drink water (stay well hydrated): Keeping your body well hydrated by drinking plenty of water each day (6-8 glasses) is essential to maintaining a healthy voice. The ...

  20. Modelling the flooding capacity of a Polish Carpathian river: A comparison of constrained and free channel conditions

    Science.gov (United States)

    Czech, Wiktoria; Radecki-Pawlik, Artur; Wyżga, Bartłomiej; Hajdukiewicz, Hanna

    2016-11-01

    The gravel-bed Biała River, Polish Carpathians, was heavily affected by channelization and channel incision in the twentieth century. Not only were these impacts detrimental to the ecological state of the river, but they also adversely modified the conditions of floodwater retention and flood wave passage. Therefore, a few years ago an erodible corridor was delimited in two sections of the Biała to enable restoration of the river. In these sections, short, channelized reaches located in the vicinity of bridges alternate with longer, unmanaged channel reaches, which either avoided channelization or in which the channel has widened after the channelization scheme ceased to be maintained. Effects of these alternating channel morphologies on the conditions for flood flows were investigated in a study of 10 pairs of neighbouring river cross sections with constrained and freely developed morphology. Discharges of particular recurrence intervals were determined for each cross section using an empirical formula. The morphology of the cross sections together with data about channel slope and roughness of particular parts of the cross sections were used as input data to the hydraulic modelling performed with the one-dimensional steady-flow HEC-RAS software. The results indicated that freely developed cross sections, usually with multithread morphology, are typified by significantly lower water depth but larger width and cross-sectional flow area at particular discharges than single-thread, channelized cross sections. They also exhibit significantly lower average flow velocity, unit stream power, and bed shear stress. The pattern of differences in the hydraulic parameters of flood flows apparent between the two types of river cross sections varies with the discharges of different frequency, and the contrasts in hydraulic parameters between unmanaged and channelized cross sections are most pronounced at low-frequency, high-magnitude floods. However, because of the deep

  1. Reproducibility of Automated Voice Range Profiles, a Systematic Literature Review

    DEFF Research Database (Denmark)

    Printz, Trine; Rosenberg, Tine; Godballe, Christian

    2018-01-01

    literature on test-retest accuracy of the automated voice range profile assessment. Study design: Systematic review. Data sources: PubMed, Scopus, Cochrane Library, ComDisDome, Embase, and CINAHL (EBSCO). Methods: We conducted a systematic literature search of six databases from 1983 to 2016. The following......Objective: Reliable voice range profiles are of great importance when measuring effects and side effects from surgery affecting voice capacity. Automated recording systems are increasingly used, but the reproducibility of results is uncertain. Our objective was to identify and review the existing...... keywords were used: phonetogram, voice range profile, and acoustic voice analysis. Inclusion criteria were automated recording procedure, healthy voices, and no intervention between test and retest. Test-retest values concerning fundamental frequency and voice intensity were reviewed. Results: Of 483...

  2. Analysis of Probability of Non-zero Secrecy Capacity for Multi-hop Networks in Presence of Hardware Impairments over Nakagami-m Fading Channels

    Directory of Open Access Journals (Sweden)

    T.-T. Phu

    2016-12-01

    Full Text Available In this paper, we evaluate probability of non-zero secrecy capacity of multi-hop relay networks over Nakagami-m fading channels in presence of hardware impairments. In the considered protocol, a source attempts to transmit its data to a destination by using multi-hop randomize-and-forward (RF strategy. The data transmitted by the source and relays are overheard by an eavesdropper. For performance evaluation, we derive exact expressions of probability of non-zero secrecy capacity (PoNSC, which are expressed by sums of infinite series of exponential functions and exponential integral functions. We then perform Monte Carlo simulations to verify the theoretical analysis.

  3. Massed versus Spaced Practice in Vocology: Effect of a Short-Term Intensive Voice Training versus a Longer-Term Traditional Voice Training

    Science.gov (United States)

    Meerschman, Iris; Van Lierde, Kristiane; Van Puyvelde, Caro; Bostyn, Astrid; Claeys, Sofie; D'haeseleer, Evelien

    2018-01-01

    Background: In contrast with most medical and pharmaceutical therapies, the optimal dosage for voice therapy or training is unknown. Aims: The aim of this study was to compare the effect of a short-term intensive voice training (IVT) with a longer-term traditional voice training (TVT) on the vocal quality and vocal capacities of vocally healthy…

  4. Crossmodal binding of fear in voice and face

    NARCIS (Netherlands)

    Dolan, R.J.; Morris, J.S.; de Gelder, B.

    2001-01-01

    In social environments, multiple sensory channels are simultaneously engaged in the service of communication. In this experiment, we were concerned with defining the neuronal mechanisms for a perceptual bias in processing simultaneously presented emotional voices and faces. Specifically, we were

  5. Evaluation of PLC Channel Capacity and ABER Performances for OFDM-Based Two-Hop Relaying Transmission

    OpenAIRE

    Ezzine, Sana; Abdelkefi, Fatma; Cances, Jean Pierre; Meghdadi, Vahid; Bouallégue, Ammar

    2017-01-01

    Powerline network is recognized as a favorable infrastructure for Smart Grid to transmit information in the network thanks to its broad coverage and low cost deployment. The existing works are trying to improve and adapt transmission techniques to reduce Powerline Communication (PLC) channel attenuation and exploit the limited bandwidth to support high data rate over long distances. Two-hop relaying BroadBand PLC (BB-PLC) system, in which Orthogonal Frequency Division Multiplexing (OFDM) is u...

  6. Dimensionality in voice quality.

    Science.gov (United States)

    Bele, Irene Velsvik

    2007-05-01

    This study concerns speaking voice quality in a group of male teachers (n = 35) and male actors (n = 36), as the purpose was to investigate normal and supranormal voices. The goal was the development of a method of valid perceptual evaluation for normal to supranormal and resonant voices. The voices (text reading at two loudness levels) had been evaluated by 10 listeners, for 15 vocal characteristics using VA scales. In this investigation, the results of an exploratory factor analysis of the vocal characteristics used in this method are presented, reflecting four dimensions of major importance for normal and supranormal voices. Special emphasis is placed on the effects on voice quality of a change in the loudness variable, as two loudness levels are studied. Furthermore, the vocal characteristics Sonority and Ringing voice quality are paid special attention, as the essence of the term "resonant voice" was a basic issue throughout a doctoral dissertation where this study was included.

  7. The role of hERG1 ion channels in epithelial-mesenchymal transition and the capacity of riluzole to reduce cisplatin resistance in colorectal cancer cells.

    Science.gov (United States)

    Fortunato, Angelo

    2017-08-01

    The transition of cells from the epithelial to the mesenchymal state (EMT) plays an important role in tumor progression. EMT allows cells to acquire mobility, stem-like behavior and resistance to apoptosis and drug treatment. These features turn EMT into a central process in tumor biology. Ion channels are attractive targets for the treatment of cancer since they play critical roles in controlling a wide range of physiological processes that are frequently deregulated in cancer. Here, we investigated the role of ether-a-go-go-related 1 (hERG1) ion channels in the EMT of colorectal cancer cells. We studied the epithelial-mesenchymal profile of different colorectal cancer-derived cell lines and the expression of hERG1 potassium channels in these cell lines using real-time PCR. Next, we knocked down hERG1 expression in HCT116 cells using lentivirus mediated RNA interference and characterized the hERG1 silenced cells in vitro and in vivo. Finally, we investigated the capacity of riluzole, an ion channel-modulating drug used in humans to treat amyotrophic lateral sclerosis, to reduce the resistance of the respective colorectal cancer cells to the chemotherapeutic drug cisplatin. We found that of the colorectal cancer-derived cell lines tested, HCT116 showed the highest mesenchymal profile and a high hERG1 expression. Subsequent hERG1 expression knockdown induced a change in cell morphology, which was accompanied by a reduction in the proliferative and tumorigenic capacities of the cells. Notably, we found that hERG1expression knockdown elicited a reversion of the EMT profile in HCT116 cells with a reacquisition of the epithelial-like profile. We also found that riluzole increased the sensitivity of HCT116 cisplatin-resistant cells to cisplatin. Our data indicate that hERG1 plays a role in the EMT of colorectal cancer cells and that its knockdown reduces the proliferative and tumorigenic capacities of these cells. In addition, we conclude that riluzole may be used in

  8. Writing with Voice

    Science.gov (United States)

    Kesler, Ted

    2012-01-01

    In this Teaching Tips article, the author argues for a dialogic conception of voice, based in the work of Mikhail Bakhtin. He demonstrates a dialogic view of voice in action, using two writing examples about the same topic from his daughter, a fifth-grade student. He then provides five practical tips for teaching a dialogic conception of voice in…

  9. Marshall’s Voice

    Directory of Open Access Journals (Sweden)

    Halper Thomas

    2017-12-01

    Full Text Available Most judicial opinions, for a variety of reasons, do not speak with the voice of identifiable judges, but an analysis of several of John Marshall’s best known opinions reveals a distinctive voice, with its characteristic language and style of argumentation. The power of this voice helps to account for the influence of his views.

  10. LMSS - From low data rate to voice services

    Science.gov (United States)

    Rogard, R.

    1992-03-01

    An overview of ESA's approach towards the introduction of Land Mobile Communications in Europe is presented. Emphasis is placed on a description of the payload called EMS to be launched on a host satellite, the Italsat-F2 spacecraft, and the definition of services which are most appropriate for a first-generation-operating Land Mobile Satellite System, namely, PRODAT, a message-handling system, and Europhone, an original approach to 'voice' systems. Attention is given to the EMS payload, characteristics, and capacity, the IF processor and channelization, and market considerations. It is shown that the optimization of the satellite characteristics and the mix of services to be provided are the key elements of a successful entry into the market.

  11. Specific features of modern voice protection systems

    Directory of Open Access Journals (Sweden)

    Roman A. Ustinov

    2017-11-01

    Full Text Available Nowadays, speech technologies are among the most vibrant sectors of the world’s economy. Of high importance is the problem of ensuring the security of speech information (SI. Here we discuss SI protection systems within a modern communication model. The model is multimodal, multithreaded, and implies a large number of subscribers interacting via several communication lines. With this in mind, we perform a detailed analysis of threats to the confidentiality, integrity and accessibility of SI. Existing methods of counteraction against these threats are discussed, and shown to be insufficient to ensure the safety of voice messages (VM in full. Mean while, there are new threats to the integrity and accessibility of SI, the solutions for which are either do not exist, or only being developed. We propose our original approach to counter these threats. Steganography methods are the most promising for ensuring the integrity of the VM.  In particular, using audiomarkers allows one to reliably trace speaker’sidentity throughout the entire communication session. In order to counter the threats to SI availability due to the capacity of the communication channel and the limited volumes of VM data storage, it is necessary to improve existing adaptive speech compression algorithms, along with developing new ones. Furthermore, such algorithms must keep the specified level of speech intelligibility.

  12. Denitrification capacity and greenhouse gas emissions of soils in channelized and restored reaches along an Alpine river corridor

    Science.gov (United States)

    Shrestha, Juna; Niklaus, Pascal; Samaritani, Emanuela; Frossard, Emmanuel; Tockner, Klement; Luster, Jörg

    2010-05-01

    In order to assess the effects of river restoration on water and air quality, the biogeochemical functions of channelized and restored river reaches have to be quantified. The objective of this study was to compare denitrification potential and greenhouse gas emissions of functional processing zones (FPZ) in a channelized and a recently restored reach of the alpine river Thur in north-eastern Switzerland. The study was part of the project cluster RECORD of the ETH domain, Switzerland, which was initiated to increase the mechanistic understanding of coupled hydrological and ecological processes in river corridors. The denitrification potential represents an important aspect of the soil filter function related to water quality. Besides, it also contributes to the emission of greenhouse gases. Extensively used pasture growing on a sandy loam is the characteristic FPZ of the channelized section. The restored section encompasses five FPZ: (i) bare gravel bars sparsely colonized by plants, (ii) gravel bars densely colonized by grass (mainly canary reed grass with up to 80 cm sandy deposits), (iii) mixed forest dominated by ash and maple, (iv) riparian forest dominated by willow (Salix alba), (v) older overbank sediments stabilized during restoration with young willows separating the forests from the river-gravel bar system (willow bush). The FPZ were sampled in January, April, August and October 2009. In addition, in June and July 2009 two flood events were monitored in the restored section with more frequent samplings. At each date, topsoil samples were collected in each FPZ (four replicates per samples) and analyzed for denitrifier enzyme activity (DEA). In addition, gas samples were taken in-situ using the closed chamber technique to measure soil respiration as well as N2O and CH4 fluxes. In all FPZ, the denitrification potential was mainly governed by soil moisture. It was highest in the willow forest exhibiting low spatial variability. The DEA in pasture, grass zone

  13. Capacity of optical communications over a lossy bosonic channel with a receiver employing the most general coherent electro-optic feedback control

    Science.gov (United States)

    Chung, Hye Won; Guha, Saikat; Zheng, Lizhong

    2017-07-01

    We study the problem of designing optical receivers to discriminate between multiple coherent states using coherent processing receivers—i.e., one that uses arbitrary coherent feedback control and quantum-noise-limited direct detection—which was shown by Dolinar to achieve the minimum error probability in discriminating any two coherent states. We first derive and reinterpret Dolinar's binary-hypothesis minimum-probability-of-error receiver as the one that optimizes the information efficiency at each time instant, based on recursive Bayesian updates within the receiver. Using this viewpoint, we propose a natural generalization of Dolinar's receiver design to discriminate M coherent states, each of which could now be a codeword, i.e., a sequence of N coherent states, each drawn from a modulation alphabet. We analyze the channel capacity of the pure-loss optical channel with a general coherent-processing receiver in the low-photon number regime and compare it with the capacity achievable with direct detection and the Holevo limit (achieving the latter would require a quantum joint-detection receiver). We show compelling evidence that despite the optimal performance of Dolinar's receiver for the binary coherent-state hypothesis test (either in error probability or mutual information), the asymptotic communication rate achievable by such a coherent-processing receiver is only as good as direct detection. This suggests that in the infinitely long codeword limit, all potential benefits of coherent processing at the receiver can be obtained by designing a good code and direct detection, with no feedback within the receiver.

  14. Singing voice outcomes following singing voice therapy.

    Science.gov (United States)

    Dastolfo-Hromack, Christina; Thomas, Tracey L; Rosen, Clark A; Gartner-Schmidt, Jackie

    2016-11-01

    The objectives of this study were to describe singing voice therapy (SVT), describe referred patient characteristics, and document the outcomes of SVT. Retrospective. Records of patients receiving SVT between June 2008 and June 2013 were reviewed (n = 51). All diagnoses were included. Demographic information, number of SVT sessions, and symptom severity were retrieved from the medical record. Symptom severity was measured via the 10-item Singing Voice Handicap Index (SVHI-10). Treatment outcome was analyzed by diagnosis, history of previous training, and SVHI-10. SVHI-10 scores decreased following SVT (mean change = 11, 40% decrease) (P singing lessons (n = 10) also completed an average of three SVT sessions. Primary muscle tension dysphonia (MTD1) and benign vocal fold lesion (lesion) were the most common diagnoses. Most patients (60%) had previous vocal training. SVHI-10 decrease was not significantly different between MTD and lesion. This is the first outcome-based study of SVT in a disordered population. Diagnosis of MTD or lesion did not influence treatment outcomes. Duration of SVT was short (approximately three sessions). Voice care providers are encouraged to partner with a singing voice therapist to provide optimal care for the singing voice. This study supports the use of SVT as a tool for the treatment of singing voice disorders. 4 Laryngoscope, 126:2546-2551, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  15. METHODS FOR QUALITY ENHANCEMENT OF USER VOICE SIGNAL IN VOICE AUTHENTICATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    O. N. Faizulaieva

    2014-03-01

    Full Text Available The reasonability for the usage of computer systems user voice in the authentication process is proved. The scientific task for improving the signal/noise ratio of the user voice signal in the authentication system is considered. The object of study is the process of input and output of the voice signal of authentication system user in computer systems and networks. Methods and means for input and extraction of voice signal against external interference signals are researched. Methods for quality enhancement of user voice signal in voice authentication systems are suggested. As modern computer facilities, including mobile ones, have two-channel audio card, the usage of two microphones is proposed in the voice signal input system of authentication system. Meanwhile, the task of forming a lobe of microphone array in a desired area of voice signal registration (100 Hz to 8 kHz is solved. The usage of directional properties of the proposed microphone array gives the possibility to have the influence of external interference signals two or three times less in the frequency range from 4 to 8 kHz. The possibilities for implementation of space-time processing of the recorded signals using constant and adaptive weighting factors are investigated. The simulation results of the proposed system for input and extraction of signals during digital processing of narrowband signals are presented. The proposed solutions make it possible to improve the value of the signal/noise ratio of the useful signals recorded up to 10, ..., 20 dB under the influence of external interference signals in the frequency range from 4 to 8 kHz. The results may be useful to specialists working in the field of voice recognition and speaker’s discrimination.

  16. Face the voice

    DEFF Research Database (Denmark)

    Lønstrup, Ansa

    2014-01-01

    will be based on a reception aesthetic and phenomenological approach, the latter as presented by Don Ihde in his book Listening and Voice. Phenomenologies of Sound , and my analytical sketches will be related to theoretical statements concerning the understanding of voice and media (Cavarero, Dolar, La......Belle, Neumark). Finally, the article will discuss the specific artistic combination and our auditory experience of mediated human voices and sculpturally projected faces in an art museum context under the general conditions of the societal panophonia of disembodied and mediated voices, as promoted by Steven...

  17. Voice and Video Telephony Services in Smartphone

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Multimedia telephony is a delay-sensitive application. Packet losses, relatively less critical than delay, are allowed up to a certain threshold. They represent the QoS constraints that have to be respected to guarantee the operation of the telephony service and user satisfaction. In this work we introduce a new smartphone architecture characterized by two process levels called application processor (AP and mobile termination (MT, respectively. Here, they communicate through a serial channel. Moreover, we focus our attention on two very important UMTS services: voice and video telephony. Through a simulation study the impact of voice and video telephony is evaluated on the structure considered using the protocols known at this moment to realize voice and video telephony

  18. Voice loops as coordination aids in space shuttle mission control.

    Science.gov (United States)

    Patterson, E S; Watts-Perotti, J; Woods, D D

    1999-01-01

    Voice loops, an auditory groupware technology, are essential coordination support tools for experienced practitioners in domains such as air traffic management, aircraft carrier operations and space shuttle mission control. They support synchronous communication on multiple channels among groups of people who are spatially distributed. In this paper, we suggest reasons for why the voice loop system is a successful medium for supporting coordination in space shuttle mission control based on over 130 hours of direct observation. Voice loops allow practitioners to listen in on relevant communications without disrupting their own activities or the activities of others. In addition, the voice loop system is structured around the mission control organization, and therefore directly supports the demands of the domain. By understanding how voice loops meet the particular demands of the mission control environment, insight can be gained for the design of groupware tools to support cooperative activity in other event-driven domains.

  19. Voice Response Systems Technology.

    Science.gov (United States)

    Gerald, Jeanette

    1984-01-01

    Examines two methods of generating synthetic speech in voice response systems, which allow computers to communicate in human terms (speech), using human interface devices (ears): phoneme and reconstructed voice systems. Considerations prior to implementation, current and potential applications, glossary, directory, and introduction to Input Output…

  20. Clinical Voices - an update

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Weed, Ethan

    Anomalous aspects of speech and voice, including pitch, fluency, and voice quality, are reported to characterise many mental disorders. However, it has proven difficult to quantify and explain this oddness of speech by employing traditional statistical methods. In this talk we will show how...

  1. Voice following radiotherapy

    International Nuclear Information System (INIS)

    Stoicheff, M.L.

    1975-01-01

    This study was undertaken to provide information on the voice of patients following radiotherapy for glottic cancer. Part I presents findings from questionnaires returned by 227 of 235 patients successfully irradiated for glottic cancer from 1960 through 1971. Part II presents preliminary findings on the speaking fundamental frequencies of 22 irradiated patients. Normal to near-normal voice was reported by 83 percent of the 227 patients; however, 80 percent did indicate persisting vocal difficulties such as fatiguing of voice with much usage, inability to sing, reduced loudness, hoarse voice quality and inability to shout. Amount of talking during treatments appeared to affect length of time for voice to recover following treatments in those cases where it took from nine to 26 weeks; also, with increasing years since treatment, patients rated their voices more favorably. Smoking habits following treatments improved significantly with only 27 percent smoking heavily as compared with 65 percent prior to radiation therapy. No correlation was found between smoking (during or after treatments) and vocal ratings or between smoking and length of time for voice to recover. There was no relationship found between reported vocal ratings and stage of the disease

  2. Voice Savers for Music Teachers

    Science.gov (United States)

    Cookman, Starr

    2012-01-01

    Music teachers are in a class all their own when it comes to voice use. These elite vocal athletes require stamina, strength, and flexibility from their voices day in, day out for hours at a time. Voice rehabilitation clinics and research show that music education ranks high among the professionals most commonly affected by voice problems.…

  3. EXPERIMENTAL STUDY OF FIRMWARE FOR INPUT AND EXTRACTION OF USER’S VOICE SIGNAL IN VOICE AUTHENTICATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    O. N. Faizulaieva

    2014-09-01

    Full Text Available Scientific task for improving the signal-to-noise ratio for user’s voice signal in computer systems and networks during the process of user’s voice authentication is considered. The object of study is the process of input and extraction of the voice signal of authentication system user in computer systems and networks. Methods and means for input and extraction of the voice signal on the background of external interference signals are investigated. Ways for quality improving of the user’s voice signal in systems of voice authentication are investigated experimentally. Firmware means for experimental unit of input and extraction of the user’s voice signal against external interference influence are considered. As modern computer means, including mobile, have two-channel audio card, two microphones are used in the voice signal input. The distance between sonic-wave sensors is 20 mm and it provides forming one direction pattern lobe of microphone array in a desired area of voice signal registration (from 100 Hz to 8 kHz. According to the results of experimental studies, the usage of directional properties of the proposed microphone array and space-time processing of the recorded signals with implementation of constant and adaptive weighting factors has made it possible to reduce considerably the influence of interference signals. The results of firmware experimental studies for input and extraction of the user’s voice signal against external interference influence are shown. The proposed solutions will give the possibility to improve the value of the signal/noise ratio of the useful signals recorded up to 20 dB under the influence of external interference signals in the frequency range from 4 to 8 kHz. The results may be useful to specialists working in the field of voice recognition and speaker discrimination.

  4. Robust matching for voice recognition

    Science.gov (United States)

    Higgins, Alan; Bahler, L.; Porter, J.; Blais, P.

    1994-10-01

    This paper describes an automated method of comparing a voice sample of an unknown individual with samples from known speakers in order to establish or verify the individual's identity. The method is based on a statistical pattern matching approach that employs a simple training procedure, requires no human intervention (transcription, work or phonetic marketing, etc.), and makes no assumptions regarding the expected form of the statistical distributions of the observations. The content of the speech material (vocabulary, grammar, etc.) is not assumed to be constrained in any way. An algorithm is described which incorporates frame pruning and channel equalization processes designed to achieve robust performance with reasonable computational resources. An experimental implementation demonstrating the feasibility of the concept is described.

  5. Voice - How humans communicate?

    Science.gov (United States)

    Tiwari, Manjul; Tiwari, Maneesha

    2012-01-01

    Voices are important things for humans. They are the medium through which we do a lot of communicating with the outside world: our ideas, of course, and also our emotions and our personality. The voice is the very emblem of the speaker, indelibly woven into the fabric of speech. In this sense, each of our utterances of spoken language carries not only its own message but also, through accent, tone of voice and habitual voice quality it is at the same time an audible declaration of our membership of particular social regional groups, of our individual physical and psychological identity, and of our momentary mood. Voices are also one of the media through which we (successfully, most of the time) recognize other humans who are important to us-members of our family, media personalities, our friends, and enemies. Although evidence from DNA analysis is potentially vastly more eloquent in its power than evidence from voices, DNA cannot talk. It cannot be recorded planning, carrying out or confessing to a crime. It cannot be so apparently directly incriminating. As will quickly become evident, voices are extremely complex things, and some of the inherent limitations of the forensic-phonetic method are in part a consequence of the interaction between their complexity and the real world in which they are used. It is one of the aims of this article to explain how this comes about. This subject have unsolved questions, but there is no direct way to present the information that is necessary to understand how voices can be related, or not, to their owners.

  6. An RFID-Based Smart Structure for the Supply Chain: Resilient Scanning Proofs and Ownership Transfer with Positive Secrecy Capacity Channels

    Science.gov (United States)

    Ortiz, Andrés

    2017-01-01

    The National Strategy for Global Supply Chain Security published in 2012 by the White House identifies two primary goals for strengthening global supply chains: first, to promote the efficient and secure movement of goods, and second to foster a resilient supply chain. The Internet of Things (IoT), and in particular Radio Frequency Identification (RFID) technology, can be used to realize these goals. For product identification, tracking and real-time awareness, RFID tags are attached to goods. As tagged goods move along the supply chain from the suppliers to the manufacturers, and then on to the retailers until eventually they reach the customers, two major security challenges can be identified: (I) to protect the shipment of goods that are controlled by potentially untrusted carriers; and (II) to secure the transfer of ownership at each stage of the chain. For the former, grouping proofs in which the tags of the scanned goods generate a proof of “simulatenous” presence can be employed, while for the latter, ownership transfer protocols (OTP) are used. This paper describes enhanced security solutions for both challenges. We first extend earlier work on grouping proofs and group codes to capture resilient group scanning with untrusted readers; then, we describe a modified version of a recently published OTP based on channels with positive secrecy capacity adapted to be implemented on common RFID systems in the supply chain. The proposed solutions take into account the limitations of low cost tags employed in the supply chain, which are only required to generate pseudorandom numbers and compute one-way hash functions. PMID:28677637

  7. An RFID-Based Smart Structure for the Supply Chain: Resilient Scanning Proofs and Ownership Transfer with Positive Secrecy Capacity Channels

    Directory of Open Access Journals (Sweden)

    Mike Burmester

    2017-07-01

    Full Text Available The National Strategy for Global Supply Chain Security published in 2012 by the White House identifies two primary goals for strengthening global supply chains: first, to promote the efficient and secure movement of goods, and second to foster a resilient supply chain. The Internet of Things (IoT, and in particular Radio Frequency Identification (RFID technology, can be used to realize these goals. For product identification, tracking and real-time awareness, RFID tags are attached to goods. As tagged goods move along the supply chain from the suppliers to the manufacturers, and then on to the retailers until eventually they reach the customers, two major security challenges can be identified: (I to protect the shipment of goods that are controlled by potentially untrusted carriers; and (II to secure the transfer of ownership at each stage of the chain. For the former, grouping proofs in which the tags of the scanned goods generate a proof of “simulatenous” presence can be employed, while for the latter, ownership transfer protocols (OTP are used. This paper describes enhanced security solutions for both challenges. We first extend earlier work on grouping proofs and group codes to capture resilient group scanning with untrusted readers; then, we describe a modified version of a recently published OTP based on channels with positive secrecy capacity adapted to be implemented on common RFID systems in the supply chain. The proposed solutions take into account the limitations of low cost tags employed in the supply chain, which are only required to generate pseudorandom numbers and compute one-way hash functions.

  8. An RFID-Based Smart Structure for the Supply Chain: Resilient Scanning Proofs and Ownership Transfer with Positive Secrecy Capacity Channels.

    Science.gov (United States)

    Burmester, Mike; Munilla, Jorge; Ortiz, Andrés; Caballero-Gil, Pino

    2017-07-04

    The National Strategy for Global Supply Chain Security published in 2012 by the White House identifies two primary goals for strengthening global supply chains: first, to promote the efficient and secure movement of goods, and second to foster a resilient supply chain. The Internet of Things (IoT), and in particular Radio Frequency Identification (RFID) technology, can be used to realize these goals. For product identification, tracking and real-time awareness, RFID tags are attached to goods. As tagged goods move along the supply chain from the suppliers to the manufacturers, and then on to the retailers until eventually they reach the customers, two major security challenges can be identified: (I) to protect the shipment of goods that are controlled by potentially untrusted carriers; and (II) to secure the transfer of ownership at each stage of the chain. For the former, grouping proofs in which the tags of the scanned goods generate a proof of "simulatenous" presence can be employed, while for the latter, ownership transfer protocols (OTP) are used. This paper describes enhanced security solutions for both challenges. We first extend earlier work on grouping proofs and group codes to capture resilient group scanning with untrusted readers; then, we describe a modified version of a recently published OTP based on channels with positive secrecy capacity adapted to be implemented on common RFID systems in the supply chain. The proposed solutions take into account the limitations of low cost tags employed in the supply chain, which are only required to generate pseudorandom numbers and compute one-way hash functions.

  9. Connections between voice ergonomic risk factors and voice symptoms, voice handicap, and respiratory tract diseases.

    Science.gov (United States)

    Rantala, Leena M; Hakala, Suvi J; Holmqvist, Sofia; Sala, Eeva

    2012-11-01

    The aim of the study was to investigate the connections between voice ergonomic risk factors found in classrooms and voice-related problems in teachers. Voice ergonomic assessment was performed in 39 classrooms in 14 elementary schools by means of a Voice Ergonomic Assessment in Work Environment--Handbook and Checklist. The voice ergonomic risk factors assessed included working culture, noise, indoor air quality, working posture, stress, and access to a sound amplifier. Teachers from the above-mentioned classrooms reported their voice symptoms, respiratory tract diseases, and completed a Voice Handicap Index (VHI). The more voice ergonomic risk factors found in the classroom the higher were the teachers' total scores on voice symptoms and VHI. Stress was the factor that correlated most strongly with voice symptoms. Poor indoor air quality increased the occurrence of laryngitis. Voice ergonomics were poor in the classrooms studied and voice ergonomic risk factors affected the voice. It is important to convey information on voice ergonomics to education administrators and those responsible for school planning and taking care of school buildings. Copyright © 2012 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  10. Double Voicing and Personhood in Collaborative Life Writing about Autism: the Transformative Narrative of Carly's Voice.

    Science.gov (United States)

    Orlando, Monica

    2018-06-01

    Collaborative memoirs by co-writers with and without autism can enable the productive interaction of the voices of the writers in ways that can empower rather than exploit the disabled subject. Carly's Voice, co-written by Arthur Fleischmann and his autistic daughter Carly, demonstrates the capacity for such life narratives to facilitate the relational interaction between writers in the negotiation of understandings of disability. Though the text begins by focusing on the limitations of life with autism, it develops into a collaboration which helps both writers move toward new ways of understanding disability and their own and one another's life stories.

  11. Speaking in Character: Voice Communication in Virtual Worlds

    Science.gov (United States)

    Wadley, Greg; Gibbs, Martin R.

    This chapter summarizes 5 years of research on the implications of introducing voice communication systems to virtual worlds. Voice introduces both benefits and problems for players of fast-paced team games, from better coordination of groups and greater social presence of fellow players on the positive side, to negative features such as channel congestion, transmission of noise, and an unwillingness by some to use voice with strangers online. Similarly, in non-game worlds like Second Life, issues related to identity and impression management play important roles, as voice may build greater trust that is especially important for business users, yet it erodes the anonymity and ability to conceal social attributes like gender that are important for other users. A very different mixture of problems and opportunities exists when users conduct several simultaneous conversations in multiple text and voice channels. Technical difficulties still exist with current systems, including the challenge of debugging and harmonizing all the participants' voice setups. Different groups use virtual worlds for very different purposes, so a single modality may not suit all.

  12. A study on the application of voice interaction in automotive human machine interface experience design

    Science.gov (United States)

    Huang, Zhaohui; Huang, Xiemin

    2018-04-01

    This paper, firstly, introduces the application trend of the integration of multi-channel interactions in automotive HMI ((Human Machine Interface) from complex information models faced by existing automotive HMI and describes various interaction modes. By comparing voice interaction and touch screen, gestures and other interaction modes, the potential and feasibility of voice interaction in automotive HMI experience design are concluded. Then, the related theories of voice interaction, identification technologies, human beings' cognitive models of voices and voice design methods are further explored. And the research priority of this paper is proposed, i.e. how to design voice interaction to create more humane task-oriented dialogue scenarios to enhance interactive experiences of automotive HMI. The specific scenarios in driving behaviors suitable for the use of voice interaction are studied and classified, and the usability principles and key elements for automotive HMI voice design are proposed according to the scenario features. Then, through the user participatory usability testing experiment, the dialogue processes of voice interaction in automotive HMI are defined. The logics and grammars in voice interaction are classified according to the experimental results, and the mental models in the interaction processes are analyzed. At last, the voice interaction design method to create the humane task-oriented dialogue scenarios in the driving environment is proposed.

  13. Voice Therapy Practices and Techniques: A Survey of Voice Clinicians.

    Science.gov (United States)

    Mueller, Peter B.; Larson, George W.

    1992-01-01

    Eighty-three voice disorder therapists' ratings of statements regarding voice therapy practices indicated that vocal nodules are the most frequent disorder treated; vocal abuse and hard glottal attack elimination, counseling, and relaxation were preferred treatment approaches; and voice therapy is more effective with adults than with children.…

  14. Smartphone App for Voice Disorders

    Science.gov (United States)

    ... on. Feature: Taste, Smell, Hearing, Language, Voice, Balance Smartphone App for Voice Disorders Past Issues / Fall 2013 ... developed a mobile monitoring device that relies on smartphone technology to gather a week's worth of talking, ...

  15. Effects of Medications on Voice

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Effects of Medications on Voice Effects of Medications on Voice Patient Health Information News ... replacement therapy post-menopause may have a variable effect. An inadequate level of thyroid replacement medication in ...

  16. Hearing Voices and Seeing Things

    Science.gov (United States)

    ... Facts for Families Guide Facts for Families - Vietnamese Hearing Voices and Seeing Things No. 102; Updated October ... delusions (a fixed, false, and often bizarre belief). Hearing voices or seeing things that are not there ...

  17. New Compensation Technique for Fiber Impairments in Ultra High Capacity Super channel Based on (QDPASK Dense wavelength division multiplex (DWDM systems

    Directory of Open Access Journals (Sweden)

    Ibrahim A.Murdas

    2017-07-01

    Full Text Available In this paper we want to increase the data rate and to get larger transmission distance, therefore we use the Advanced modulation technique QDPASK in DWDM system with low channels space. In case of long transmission distance and multi channels system both giving rise to inter channel crosstalk induced by fiber nonlinearities as a result the use of advanced modulation technique becomes difficult. In this paper Quaternary differential phase amplitude shift keying (QDPASK is designed for 32 dense wavelength division multiplexing (DWDM channels, therefore we proposed a new cascade compensation system consist of optical and digital back propagation techniques (ODBP for compensate the linear and nonlinear effects . A performance of the system was reported using QDPASK DWDM fiber-optic system for various system parameters. The research is tested in VPI maker environment.

  18. Aerodynamic and sound intensity measurements in tracheoesophageal voice

    NARCIS (Netherlands)

    Grolman, Wilko; Eerenstein, Simone E. J.; Tan, Frédérique M. L.; Tange, Rinze A.; Schouwenburg, Paul F.

    2007-01-01

    BACKGROUND: In laryngectomized patients, tracheoesophageal voice generally provides a better voice quality than esophageal voice. Understanding the aerodynamics of voice production in patients with a voice prosthesis is important for optimizing prosthetic designs and successful voice rehabilitation.

  19. [Voice disorders in female teachers assessed by Voice Handicap Index].

    Science.gov (United States)

    Niebudek-Bogusz, Ewa; Kuzańska, Anna; Woźnicka, Ewelina; Sliwińska-Kowalska, Mariola

    2007-01-01

    The aim of this study was to assess the application of Voice Handicap Index (VHI) in the diagnosis of occupational voice disorders in female teachers. The subjective assessment of voice by VHI was performed in fifty subjects with dysphonia diagnosed in laryngovideostroboscopic examination. The control group comprised 30 women whose jobs did not involve vocal effort. The results of the total VHI score and each of its subscales: functional, emotional and physical was significantly worse in the study group than in controls (p teachers estimated their own voice problems as a moderate disability, while 12% of them reported severe voice disability. However, all non-teachers assessed their voice problems as slight, their results ranged at the lowest level of VHI score. This study confirmed that VHI as a tool for self-assessment of voice can be a significant contribution to the diagnosis of occupational dysphonia.

  20. Listen to a voice

    DEFF Research Database (Denmark)

    Hølge-Hazelton, Bibi

    2001-01-01

    Listen to the voice of a young girl Lonnie, who was diagnosed with Type 1 diabetes at 16. Imagine that she is deeply involved in the social security system. She lives with her mother and two siblings in a working class part of a small town. She is at a special school for problematic youth, and her...

  1. Sustainable Consumer Voices

    DEFF Research Database (Denmark)

    Klitmøller, Anders; Rask, Morten; Jensen, Nevena

    2011-01-01

    Aiming to explore how user driven innovation can inform high level design strategies, an in-depth empirical study was carried out, based on data from 50 observations of private vehicle users. This paper reports the resulting 5 consumer voices: Technology Enthusiast, Environmentalist, Design Lover...

  2. Voices of courage

    Directory of Open Access Journals (Sweden)

    Noraida Abdullah Karim

    2007-07-01

    Full Text Available In May 2007 the Women’s Commission for Refugee Women and Children1 presented its annual Voices of Courage awards to three displaced people who have dedicated their lives to promoting economic opportunities for refugee and displaced women and youth. These are their (edited testimonies.

  3. What the voice reveals

    NARCIS (Netherlands)

    Ko, Sei Jin

    2007-01-01

    Given that the voice is our main form of communication, we know surprisingly little about how it impacts judgment and behavior. Furthermore, the modern advancement in telecommunication systems, such as cellular phones, has meant that a large proportion of our everyday interactions are conducted

  4. Bodies and Voices

    DEFF Research Database (Denmark)

    A wide-ranging collection of essays centred on readings of the body in contemporary literary and socio-anthropological discourse, from slavery and rape to female genital mutilation, from clothing, ocular pornography, voice, deformation and transmutation to the imprisoned, dismembered, remembered...

  5. Human voice perception.

    Science.gov (United States)

    Latinus, Marianne; Belin, Pascal

    2011-02-22

    We are all voice experts. First and foremost, we can produce and understand speech, and this makes us a unique species. But in addition to speech perception, we routinely extract from voices a wealth of socially-relevant information in what constitutes a more primitive, and probably more universal, non-linguistic mode of communication. Consider the following example: you are sitting in a plane, and you can hear a conversation in a foreign language in the row behind you. You do not see the speakers' faces, and you cannot understand the speech content because you do not know the language. Yet, an amazing amount of information is available to you. You can evaluate the physical characteristics of the different protagonists, including their gender, approximate age and size, and associate an identity to the different voices. You can form a good idea of the different speaker's mood and affective state, as well as more subtle cues as the perceived attractiveness or dominance of the protagonists. In brief, you can form a fairly detailed picture of the type of social interaction unfolding, which a brief glance backwards can on the occasion help refine - sometimes surprisingly so. What are the acoustical cues that carry these different types of vocal information? How does our brain process and analyse this information? Here we briefly review an emerging field and the main tools used in voice perception research. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Voice application development for Android

    CERN Document Server

    McTear, Michael

    2013-01-01

    This book will give beginners an introduction to building voice-based applications on Android. It will begin by covering the basic concepts and will build up to creating a voice-based personal assistant. By the end of this book, you should be in a position to create your own voice-based applications on Android from scratch in next to no time.Voice Application Development for Android is for all those who are interested in speech technology and for those who, as owners of Android devices, are keen to experiment with developing voice apps for their devices. It will also be useful as a starting po

  7. Voice similarity in identical twins.

    Science.gov (United States)

    Van Gysel, W D; Vercammen, J; Debruyne, F

    2001-01-01

    If people are asked to discriminate visually the two individuals of a monozygotic twin (MT), they mostly get into trouble. Does this problem also exist when listening to twin voices? Twenty female and 10 male MT voices were randomly assembled with one "strange" voice to get voice trios. The listeners (10 female students in Speech and Language Pathology) were asked to label the twins (voices 1-2, 1-3 or 2-3) in two conditions: two standard sentences read aloud and a 2.5-second midsection of a sustained /a/. The proportion correctly labelled twins was for female voices 82% and 63% and for male voices 74% and 52% for the sentences and the sustained /a/ respectively, both being significantly greater than chance (33%). The acoustic analysis revealed a high intra-twin correlation for the speaking fundamental frequency (SFF) of the sentences and the fundamental frequency (F0) of the sustained /a/. So the voice pitch could have been a useful characteristic in the perceptual identification of the twins. We conclude that there is a greater perceptual resemblance between the voices of identical twins than between voices without genetic relationship. The identification however is not perfect. The voice pitch possibly contributes to the correct twin identifications.

  8. Compound Wiretap Channels

    Directory of Open Access Journals (Sweden)

    Shlomo Shamai (Shitz

    2009-01-01

    Full Text Available This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom (s.d.o.f. are derived for the degraded case with one receiver. Schemes to achieve the s.d.o.f. for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable s.d.o.f. is given for the general case.

  9. Compound Wiretap Channels

    Directory of Open Access Journals (Sweden)

    Kramer Gerhard

    2009-01-01

    Full Text Available Abstract This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom ( are derived for the degraded case with one receiver. Schemes to achieve the for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable is given for the general case.

  10. Advanced distributed simulation technology: Digital Voice Gateway Reference Guide

    Science.gov (United States)

    Vanhook, Dan; Stadler, Ed

    1994-01-01

    The Digital Voice Gateway (referred to as the 'DVG' in this document) transmits and receives four full duplex encoded speech channels over the Ethernet. The information in this document applies only to DVG's running firmware of the version listed on the title page. This document, previously named Digital Voice Gateway Reference Guide, BBN Systems and Technologies Corporation, Cambridge, MA 02138, was revised for revision 2.00. This new revision changes the network protocol used by the DVG, to comply with the SINCGARS radio simulation (For SIMNET 6.6.1). Because of the extensive changes to revision 2.00 a separate document was created rather than supplying change pages.

  11. Risk factors for voice problems in teachers.

    NARCIS (Netherlands)

    Kooijman, P.G.C.; Jong, F.I.C.R.S. de; Thomas, G.; Huinck, W.J.; Donders, A.R.T.; Graamans, K.; Schutte, H.K.

    2006-01-01

    In order to identify factors that are associated with voice problems and voice-related absenteeism in teachers, 1,878 questionnaires were analysed. The questionnaires inquired about personal data, voice complaints, voice-related absenteeism from work and conditions that may lead to voice complaints

  12. Risk factors for voice problems in teachers

    NARCIS (Netherlands)

    Kooijman, P. G. C.; de Jong, F. I. C. R. S.; Thomas, G.; Huinck, W.; Donders, R.; Graamans, K.; Schutte, H. K.

    2006-01-01

    In order to identify factors that are associated with voice problems and voice-related absenteeism in teachers, 1,878 questionnaires were analysed. The questionnaires inquired about personal data, voice complaints, voice-related absenteeism from work and conditions that may lead to voice complaints

  13. You're a What? Voice Actor

    Science.gov (United States)

    Liming, Drew

    2009-01-01

    This article talks about voice actors and features Tony Oliver, a professional voice actor. Voice actors help to bring one's favorite cartoon and video game characters to life. They also do voice-overs for radio and television commercials and movie trailers. These actors use the sound of their voice to sell a character's emotions--or an advertised…

  14. Voice search for development

    CSIR Research Space (South Africa)

    Barnard, E

    2010-09-01

    Full Text Available of speech technology development, similar approaches are likely to be applicable in both circumstances. However, within these broad approaches there are details which are specific to certain languages (or lan- guage families) that may require solutions... to the modeling of pitch were therefore required. Similarly, it is possible that novel solutions will be required to deal with the click sounds that occur in some Southern Bantu languages, or the voicing Copyright  2010 ISCA 26-30 September 2010, Makuhari...

  15. "Critical Bureaucracy" in Action: Embedding Student Voice into School Governance

    Science.gov (United States)

    Carlile, Anna

    2012-01-01

    This article suggests a model for "youth voice" based on a participatory research methodology, "Illuminate". The article reports on research into the capacity for "Illuminate" to amount to "critical bureaucracy". Critical bureaucracy is presented as an approach to governance activities (here, in schools and further education colleges) which is…

  16. Syllogisms delivered in an angry voice lead to improved performance and engagement of a different neural system compared to neutral voice

    OpenAIRE

    Kathleen Walton Smith; Laura-Lee eBalkwill; Oshin eVartanian; Vinod eGoel; Vinod eGoel

    2015-01-01

    Despite the fact that most real-world reasoning occurs in some emotional context, very little is known about the underlying behavioral and neural implications of such context. To further understand the role of emotional context in logical reasoning we scanned 15 participants with fMRI while they engaged in logical reasoning about neutral syllogisms presented through the auditory channel in a sad, angry, or neutral tone of voice. Exposure to angry voice led to improved reasoning performance co...

  17. Voice and silence in organizations

    Directory of Open Access Journals (Sweden)

    Moaşa, H.

    2011-01-01

    Full Text Available Unlike previous research on voice and silence, this article breaksthe distance between the two and declines to treat them as opposites. Voice and silence are interrelated and intertwined strategic forms ofcommunication which presuppose each other in such a way that the absence of one would minimize completely the other’s presence. Social actors are not voice, or silence. Social actors can have voice or silence, they can do both because they operate at multiple levels and deal with multiple issues at different moments in time.

  18. Voice Biometrics for Information Assurance Applications

    National Research Council Canada - National Science Library

    Kang, George

    2002-01-01

    .... The ultimate goal of voice biometrics is to enable the use of voice as a password. Voice biometrics are "man-in-the-loop" systems in which system performance is significantly dependent on human performance...

  19. Objective voice parameters in Colombian school workers with healthy voices

    NARCIS (Netherlands)

    L.C. Cantor Cutiva (Lady Catherine); A. Burdorf (Alex)

    2015-01-01

    textabstractObjectives: To characterize the objective voice parameters among school workers, and to identify associated factors of three objective voice parameters, namely fundamental frequency, sound pressure level and maximum phonation time. Materials and methods: We conducted a cross-sectional

  20. Pedagogic Voice: Student Voice in Teaching and Engagement Pedagogies

    Science.gov (United States)

    Baroutsis, Aspa; McGregor, Glenda; Mills, Martin

    2016-01-01

    In this paper, we are concerned with the notion of "pedagogic voice" as it relates to the presence of student "voice" in teaching, learning and curriculum matters at an alternative, or second chance, school in Australia. This school draws upon many of the principles of democratic schooling via its utilisation of student voice…

  1. Effectiveness of a Voice Training Program for Student Teachers on Vocal Health.

    Science.gov (United States)

    Richter, Bernhard; Nusseck, Manfred; Spahn, Claudia; Echternach, Matthias

    2016-07-01

    The effectiveness of a preventive training program on vocal health for German student teachers was investigated on specific vocal parameters. The voice quality as described by the Dysphonia Severity Index of 204 student teachers (training group: n = 123; control group: n = 81) was measured at the beginning and at the end of the student teachers training period (duration 1.5 years). Additionally, for investigating the voice-carrying capacity, a vocal loading test (VLT) was performed. Finally, participants had to provide a subjective judgment of a possible Voice Handicap Index. The training program improved the voice quality of the trained group compared with that of the control group, whose voice quality declined. The trained group was also able to better sustain their voice quality across the VLT than the control group. Both groups, however, reported a similar increase in subjective vocal strain. The presented training program clearly showed a positive impact on the voice quality and the vocal capacity. The results maintain the importance of such a training program to be integrated in the education and occupational routine of teachers. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  2. Facing Sound - Voicing Art

    DEFF Research Database (Denmark)

    Lønstrup, Ansa

    2013-01-01

    This article is based on examples of contemporary audiovisual art, with a special focus on the Tony Oursler exhibition Face to Face at Aarhus Art Museum ARoS in Denmark in March-July 2012. My investigation involves a combination of qualitative interviews with visitors, observations of the audience´s...... interactions with the exhibition and the artwork in the museum space and short analyses of individual works of art based on reception aesthetics and phenomenology and inspired by newer writings on sound, voice and listening....

  3. Voice over IP Security

    CERN Document Server

    Keromytis, Angelos D

    2011-01-01

    Voice over IP (VoIP) and Internet Multimedia Subsystem technologies (IMS) are rapidly being adopted by consumers, enterprises, governments and militaries. These technologies offer higher flexibility and more features than traditional telephony (PSTN) infrastructures, as well as the potential for lower cost through equipment consolidation and, for the consumer market, new business models. However, VoIP systems also represent a higher complexity in terms of architecture, protocols and implementation, with a corresponding increase in the potential for misuse. In this book, the authors examine the

  4. Bodies, Spaces, Voices, Silences

    OpenAIRE

    Donatella Mazzoleni; Pietro Vitiello

    2013-01-01

    A good architecture should not only allow functional, formal and technical quality for urban spaces, but also let the voice of the city be perceived, listened, enjoyed. Every city has got its specific sound identity, or “ISO” (R. O. Benenzon), made up of a complex texture of background noises and fluctuation of sound figures emerging and disappearing in a game of continuous fadings. For instance, the ISO of Naples is characterized by a spread need of hearing the sound return of one’s/others v...

  5. Preference for leaders with masculine voices holds in the case of feminine leadership roles.

    Science.gov (United States)

    Anderson, Rindy C; Klofstad, Casey A

    2012-01-01

    Human voice pitch research has focused on perceptions of attractiveness, strength, and social dominance. Here we examine the influence of pitch on selection of leaders, and whether this influence varies by leadership role. Male and female leaders with lower-pitched (i.e., masculine) voices are generally preferred by both men and women. We asked whether this preference shifts to favor higher-pitch (i.e., feminine) voices within the specific context of leadership positions that are typically held by women (i.e., feminine leadership roles). In hypothetical elections for two such positions, men and women listened to pairs of male and female voices that differed only in pitch, and were asked which of each pair they would vote for. As in previous studies, men and women preferred female candidates with masculine voices. Likewise, men preferred men with masculine voices. Women, however, did not discriminate between male voices. Overall, contrary to research showing that perceptions of voice pitch can be influenced by social context, these results suggest that the influence of voice pitch on perceptions of leadership capacity is largely consistent across different domains of leadership.

  6. Preference for leaders with masculine voices holds in the case of feminine leadership roles.

    Directory of Open Access Journals (Sweden)

    Rindy C Anderson

    Full Text Available Human voice pitch research has focused on perceptions of attractiveness, strength, and social dominance. Here we examine the influence of pitch on selection of leaders, and whether this influence varies by leadership role. Male and female leaders with lower-pitched (i.e., masculine voices are generally preferred by both men and women. We asked whether this preference shifts to favor higher-pitch (i.e., feminine voices within the specific context of leadership positions that are typically held by women (i.e., feminine leadership roles. In hypothetical elections for two such positions, men and women listened to pairs of male and female voices that differed only in pitch, and were asked which of each pair they would vote for. As in previous studies, men and women preferred female candidates with masculine voices. Likewise, men preferred men with masculine voices. Women, however, did not discriminate between male voices. Overall, contrary to research showing that perceptions of voice pitch can be influenced by social context, these results suggest that the influence of voice pitch on perceptions of leadership capacity is largely consistent across different domains of leadership.

  7. Perceptual adaptation of voice gender discrimination with spectrally shifted vowels.

    Science.gov (United States)

    Li, Tianhao; Fu, Qian-Jie

    2011-08-01

    To determine whether perceptual adaptation improves voice gender discrimination of spectrally shifted vowels and, if so, which acoustic cues contribute to the improvement. Voice gender discrimination was measured for 10 normal-hearing subjects, during 5 days of adaptation to spectrally shifted vowels, produced by processing the speech of 5 male and 5 female talkers with 16-channel sine-wave vocoders. The subjects were randomly divided into 2 groups; one subjected to 50-Hz, and the other to 200-Hz, temporal envelope cutoff frequencies. No preview or feedback was provided. There was significant adaptation in voice gender discrimination with the 200-Hz cutoff frequency, but significant improvement was observed only for 3 female talkers with F(0) > 180 Hz and 3 male talkers with F(0) gender discrimination under spectral shift conditions with perceptual adaptation, but spectral shift may limit the exclusive use of spectral information and/or the use of formant structure on voice gender discrimination. The results have implications for cochlear implant users and for understanding voice gender discrimination.

  8. Controlling An Electric Car Starter System Through Voice

    Directory of Open Access Journals (Sweden)

    A.B. Muhammad Firdaus

    2015-04-01

    Full Text Available Abstract These days automotive has turned into a stand out amongst the most well-known modes of transportation on the grounds that a large number of Malaysians could bear to have an auto. There are numerous decisions of innovations in auto that have in the market. One of the engineering is voice controlled framework. Voice Recognition is the procedure of consequently perceiving a certain statement talked by a specific speaker focused around individual data included in discourse waves. This paper is to make an car controlled by voice of human. An essential pre-processing venture in Voice Recognition systems is to recognize the vicinity of noise. Sensitivity to speech variability lacking recognition precision and helplessness to mimic are among the principle specialized obstacles that keep the far reaching selection of speech-based recognition systems. Voice recognition systems work sensibly well with a quiet conditions however inadequately under loud conditions or in twisted channels. The key focus of the project is to control an electric car starter system.

  9. Voice, Schooling, Inequality, and Scale

    Science.gov (United States)

    Collins, James

    2013-01-01

    The rich studies in this collection show that the investigation of voice requires analysis of "recognition" across layered spatial-temporal and sociolinguistic scales. I argue that the concepts of voice, recognition, and scale provide insight into contemporary educational inequality and that their study benefits, in turn, from paying attention to…

  10. The Voices of the Documentarist

    Science.gov (United States)

    Utterback, Ann S.

    1977-01-01

    Discusses T. S. Elliot's essay, "The Three Voices of Poetry" which conceptualizes the position taken by the poet or creator. Suggests that an examination of documentary film, within the three voices concept, expands the critical framework of the film genre. (MH)

  11. Bodies, Spaces, Voices, Silences

    Directory of Open Access Journals (Sweden)

    Donatella Mazzoleni

    2013-07-01

    Full Text Available A good architecture should not only allow functional, formal and technical quality for urban spaces, but also let the voice of the city be perceived, listened, enjoyed. Every city has got its specific sound identity, or “ISO” (R. O. Benenzon, made up of a complex texture of background noises and fluctuation of sound figures emerging and disappearing in a game of continuous fadings. For instance, the ISO of Naples is characterized by a spread need of hearing the sound return of one’s/others voices, by a hate of silence. Cities may fall ill: illness from noise, within super-crowded neighbourhoods, or illness from silence, in the forced isolation of peripheries. The proposal of an urban music therapy denotes an unpublished and innovative enlarged interdisciplinary research path, where architecture, music, medicine, psychology, communication science may converge, in order to work for rebalancing spaces and relation life of the urban collectivity, through the care of body and sound dimensions.

  12. 80-Channel Multiplexer-Demultiplexer Module for DWDM Communications using Hybrid AWG -- Interleaver Technology

    Science.gov (United States)

    Rablau, Corneliu; Bredthauer, Lance

    2007-10-01

    Aside from the more traditional data, voice and e-mail communications, new bandwidth intensive applications in the larger consumer markets, such as music, digital pictures and movies, have led to an explosive increase in the demand for transmission capacity for optical communications networks. This has resulted in a widespread deployment of Dense Wavelength Division Multiplexing (DWDM) as a means of increasing the communications capacity by multiplexing and transmitting signals of different wavelengths (establishing multiple communication channels) through a single strand of fiber. We report on the design, assembly and characterization of a 50-GHz, 80-channel Mux-Demux module for DWDM systems. The module has been assembled from two commercially available 100 GHz, 40-channel Array Waveguide Grating (AWG) modules and a 50-GHz to 100-GHz interleaver. Relevant performance parameters such as insertion loss, channel uniformity, next-channel isolation (crosstalk) and integrated cross-talk are presented and discussed in contrast with the performance of other competing technologies such as Thin-Film-Filter-based Mux-Demux devices.

  13. Success with voice recognition.

    Science.gov (United States)

    Sferrella, Sheila M

    2003-01-01

    You need a compelling reason to implement voice recognition technology. At my institution, the compelling reason was a turnaround time for Radiology results of more than two days. Only 41 percent of our reports were transcribed and signed within 24 hours. In November 1998, a team from Lehigh Valley Hospital went to RSNA and reviewed every voice system on the market. The evaluation was done with the radiologist workflow in mind, and we came back from the meeting with the vendor selection completed. The next steps included developing a business plan, approval of funds, reference calls to more than 15 sites and contract negotiation, all of which took about six months. The department of Radiology at Lehigh Valley Hospital and Health Network (LVHHN) is a multi-site center that performs over 360,000 procedures annually. The department handles all modalities of radiology: general diagnosis, neuroradiology, ultrasound, CT Scan, MRI, interventional radiology, arthography, myelography, bone densitometry, nuclear medicine, PET imaging, vascular lab and other advanced procedures. The department consists of 200 FTEs and a medical staff of more than 40 radiologists. The budget is in the $10.3 million range. There are three hospital sites and four outpatient imaging center sites where services are provided. At Lehigh Valley Hospital, radiologists are not dedicated to one subspecialty, so implementing a voice system by modality was not an option. Because transcription was so far behind, we needed to eliminate that part of the process. As a result, we decided to deploy the system all at once and with the radiologists as editors. The planning and testing phase took about four months, and the implementation took two weeks. We deployed over 40 workstations and trained close to 50 physicians. The radiologists brought in an extra radiologist from our group for the two weeks of training. That allowed us to train without taking a radiologist out of the department. We trained three to six

  14. Analysis of Cell Signal Transduction Based on Kullback–Leibler Divergence: Channel Capacity and Conservation of Its Production Rate during Cascade

    Directory of Open Access Journals (Sweden)

    Tatsuaki Tsuruyama

    2018-06-01

    Full Text Available Kullback–Leibler divergence (KLD is a type of extended mutual entropy, which is used as a measure of information gain when transferring from a prior distribution to a posterior distribution. In this study, KLD is applied to the thermodynamic analysis of cell signal transduction cascade and serves an alternative to mutual entropy. When KLD is minimized, the divergence is given by the ratio of the prior selection probability of the signaling molecule to the posterior selection probability. Moreover, the information gain during the entire channel is shown to be adequately described by average KLD production rate. Thus, this approach provides a framework for the quantitative analysis of signal transduction. Moreover, the proposed approach can identify an effective cascade for a signaling network.

  15. Effects of dietary sweet potato leaf meal on the growth, non-specific immune responses, total phenols and antioxidant capacity in channel catfish (Ictalurus punctatus).

    Science.gov (United States)

    Lochmann, Rebecca T; Islam, Shahidul; Phillips, Harold; Adam, Zelalem; Everette, Jace

    2013-04-01

    Traditional energy sources in catfish diets have become costly, and economical alternatives are needed. Sweet potato leaves are underutilised agricultural by-products that provide energy and substantial amounts of phenols, which affect animal and human health. There is little information on the effects of these compounds on catfish, or the capacity of catfish to accumulate dietary phenols. Catfish enriched with phenols have marketing potential as functional foods. This study investigated the effects of diets with sweet potato leaf meal (SPLM) on growth performance, health and total phenolic compounds in catfish. SPLM was substituted for wheat middlings in three diets fed to groups of juvenile catfish for 10 weeks. Weight gain, feed conversion, survival, alternative complement activity and lysozyme activity were similar among diets. Haematocrit was lower in fish fed diets with SPLM, but within the normal range. Total phenols and antioxidant capacity in the whole body were similar among treatments. SPLM was an effective energy source for catfish up to the maximum level tested (230 g kg(-1) diet). SPLM did not enhance total phenols in catfish, but there were no apparent antinutritional effects of the meal on catfish growth, health or survival. © 2012 Society of Chemical Industry.

  16. Crossing Cultures with Multi-Voiced Journals

    Science.gov (United States)

    Styslinger, Mary E.; Whisenant, Alison

    2004-01-01

    In this article, the authors discuss the benefits of using multi-voiced journals as a teaching strategy in reading instruction. Multi-voiced journals, an adaptation of dual-voiced journals, encourage responses to reading in varied, cultured voices of characters. It is similar to reading journals in that they prod students to connect to the lives…

  17. Optimal super dense coding over memory channels

    OpenAIRE

    Shadman, Zahra; Kampermann, Hermann; Macchiavello, Chiara; Bruß, Dagmar

    2011-01-01

    We study the super dense coding capacity in the presence of quantum channels with correlated noise. We investigate both the cases of unitary and non-unitary encoding. Pauli channels for arbitrary dimensions are treated explicitly. The super dense coding capacity for some special channels and resource states is derived for unitary encoding. We also provide an example of a memory channel where non-unitary encoding leads to an improvement in the super dense coding capacity.

  18. Voice synthesis application

    Science.gov (United States)

    Lightstone, P. C.; Davidson, W. M.

    1982-04-01

    The military detection assessment laboratory houses an experimental field system which assesses different alarm indicators such as fence disturbance sensors, MILES cables, and microwave Racons. A speech synthesis board which could be interfaced, by means of a computer, to an alarm logger making verbal acknowledgement of alarms possible was purchased. Different products and different types of voice synthesis were analyzed before a linear predictive code device produced by Telesensory Speech Systems of Palo Alto, California was chosen. This device is called the Speech 1000 Board and has a dedicated 8085 processor. A multiplexer card was designed and the Sp 1000 interfaced through the card into a TMS 990/100M Texas Instrument microcomputer. It was also necessary to design the software with the capability of recognizing and flagging an alarm on any 1 of 32 possible lines. The experimental field system was then packaged with a dc power supply, LED indicators, speakers, and switches, and deployed in the field performing reliably.

  19. How to help teachers' voices.

    Science.gov (United States)

    Saatweber, Margarete

    2008-01-01

    It has been shown that teachers are at high risk of developing occupational dysphonia, and it has been widely accepted that the vocal characteristics of a speaker play an important role in determining the reactions of listeners. The functions of breathing, breathing movement, breathing tonus, voice vibrations and articulation tonus are transmitted to the listener. So we may conclude that listening to the teacher's voice at school influences children's behavior and the perception of spoken language. This paper presents the concept of Schlaffhorst-Andersen including exercises to help teachers improve their voice, breathing, movement and their posture. Copyright 2008 S. Karger AG, Basel.

  20. Voice stress analysis and evaluation

    Science.gov (United States)

    Haddad, Darren M.; Ratley, Roy J.

    2001-02-01

    Voice Stress Analysis (VSA) systems are marketed as computer-based systems capable of measuring stress in a person's voice as an indicator of deception. They are advertised as being less expensive, easier to use, less invasive in use, and less constrained in their operation then polygraph technology. The National Institute of Justice have asked the Air Force Research Laboratory for assistance in evaluating voice stress analysis technology. Law enforcement officials have also been asking questions about this technology. If VSA technology proves to be effective, its value for military and law enforcement application is tremendous.

  1. Voice Habits and Behaviors: Voice Care Among Flamenco Singers.

    Science.gov (United States)

    Garzón García, Marina; Muñoz López, Juana; Y Mendoza Lara, Elvira

    2017-03-01

    The purpose of this study is to analyze the vocal behavior of flamenco singers, as compared with classical music singers, to establish a differential vocal profile of voice habits and behaviors in flamenco music. Bibliographic review was conducted, and the Singer's Vocal Habits Questionnaire, an experimental tool designed by the authors to gather data regarding hygiene behavior, drinking and smoking habits, type of practice, voice care, and symptomatology perceived in both the singing and the speaking voice, was administered. We interviewed 94 singers, divided into two groups: the flamenco experimental group (FEG, n = 48) and the classical control group (CCG, n = 46). Frequency analysis, a Likert scale, and discriminant and exploratory factor analysis were used to obtain a differential profile for each group. The FEG scored higher than the CCG in speaking voice symptomatology. The FEG scored significantly higher than the CCG in use of "inadequate vocal technique" when singing. Regarding voice habits, the FEG scored higher in "lack of practice and warm-up" and "environmental habits." A total of 92.6% of the subjects classified themselves correctly in each group. The Singer's Vocal Habits Questionnaire has proven effective in differentiating flamenco and classical singers. Flamenco singers are exposed to numerous vocal risk factors that make them more prone to vocal fatigue, mucosa dehydration, phonotrauma, and muscle stiffness than classical singers. Further research is needed in voice training in flamenco music, as a means to strengthen the voice and enable it to meet the requirements of this musical genre. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  2. The role of spectral and temporal cues in voice gender discrimination by normal-hearing listeners and cochlear implant users.

    Science.gov (United States)

    Fu, Qian-Jie; Chinchilla, Sherol; Galvin, John J

    2004-09-01

    The present study investigated the relative importance of temporal and spectral cues in voice gender discrimination and vowel recognition by normal-hearing subjects listening to an acoustic simulation of cochlear implant speech processing and by cochlear implant users. In the simulation, the number of speech processing channels ranged from 4 to 32, thereby varying the spectral resolution; the cutoff frequencies of the channels' envelope filters ranged from 20 to 320 Hz, thereby manipulating the available temporal cues. For normal-hearing subjects, results showed that both voice gender discrimination and vowel recognition scores improved as the number of spectral channels was increased. When only 4 spectral channels were available, voice gender discrimination significantly improved as the envelope filter cutoff frequency was increased from 20 to 320 Hz. For all spectral conditions, increasing the amount of temporal information had no significant effect on vowel recognition. Both voice gender discrimination and vowel recognition scores were highly variable among implant users. The performance of cochlear implant listeners was similar to that of normal-hearing subjects listening to comparable speech processing (4-8 spectral channels). The results suggest that both spectral and temporal cues contribute to voice gender discrimination and that temporal cues are especially important for cochlear implant users to identify the voice gender when there is reduced spectral resolution.

  3. Voice and choice by delegation.

    Science.gov (United States)

    van de Bovenkamp, Hester; Vollaard, Hans; Trappenburg, Margo; Grit, Kor

    2013-02-01

    In many Western countries, options for citizens to influence public services are increased to improve the quality of services and democratize decision making. Possibilities to influence are often cast into Albert Hirschman's taxonomy of exit (choice), voice, and loyalty. In this article we identify delegation as an important addition to this framework. Delegation gives individuals the chance to practice exit/choice or voice without all the hard work that is usually involved in these options. Empirical research shows that not many people use their individual options of exit and voice, which could lead to inequality between users and nonusers. We identify delegation as a possible solution to this problem, using Dutch health care as a case study to explore this option. Notwithstanding various advantages, we show that voice and choice by delegation also entail problems of inequality and representativeness.

  4. Voice Force tulekul / Tõnu Ojala

    Index Scriptorium Estoniae

    Ojala, Tõnu, 1969-

    2005-01-01

    60. sünnipäeva tähistava Tallinna Tehnikaülikooli Akadeemilise Meeskoori juubelihooaja üritusest - a capella pop-gruppide festivalist Voice Force (kontserdid 12. nov. klubis Parlament ja 3. dets. Vene Kultuurikeskuses)

  5. Taking Care of Your Voice

    Science.gov (United States)

    ... negative effect on voice. Exercise regularly. Exercise increases stamina and muscle tone. This helps provide good posture ... testing man-made and biological materials and stem cell technologies that may eventually be used to engineer ...

  6. The Christian voice in philosophy

    Directory of Open Access Journals (Sweden)

    Stuart Fowler

    1982-03-01

    Full Text Available In this paper the Rev. Stuart Fowler outlines a Christian voice in Philosophy and urges the Christian philosopher to investigate his position and his stance with integrity and honesty.

  7. Voice over IP in Wireless Heterogeneous Networks

    DEFF Research Database (Denmark)

    Fathi, Hanane; Chakraborty, Shyam; Prasad, Ramjee

    with the deployment of wireless heterogeneous systems, both speech and data traffic are carrried over wireless links by the same IP-based packet-switched infrastructure. However, this combination faces some challenges due to the inherent properties of the wireless network. The requirements for good quality VoIP...... communications are difficult to achieve in a time-varying environment due to channel errors and traffic congestion and across different systems. The provision of VoIP in wireless heterogeneous networks requires a set of time-efficient control mechanisms to support a VoIP session with acceptable quality....... The focus of Voice over IP in Wierless Heterogeneous Networks is on mechanisms that affect the VoIP user satisfaction  while not explicitly involved in the media session. This relates to the extra delays introduced by the security and the signaling protocols used to set up an authorized VoIP session...

  8. Modeling and analysis of voice and data in cognitive radio networks

    CERN Document Server

    Gunawardena, Subodha

    2014-01-01

    This Springer Brief investigates the voice and elastic/interactive data service support over cognitive radio networks (CRNs), in terms of their delay requirements. The increased demand for wireless communication conflicts with the scarcity of the radio spectrum, but CRNS allow for more efficient use of the networks. The authors review packet level delay requirements of the voice service and session level delay requirements of the elastic/interactive data services, particularly constant-rate and on-o? voice tra?c capacities in CRNs with centralized and distributed network coordination. Some gen

  9. Resource Planning for Voice over Wireless Both-Way Transmission Media

    Directory of Open Access Journals (Sweden)

    B. Tsankov

    2008-04-01

    Full Text Available The medium in IEEE 802.11- and IEEE 802.16-based networks for voice communications can be considered "both-way" - for transmission and reception. Therefore, the packet arrivals for voice dialogue services in such networks are not strictly independent. In this paper, we discuss the traffic capacity in the call (network layer and suggest accounting for the impact of the correlated nature of two-way voice conversations on performance estimation. We present analytical results and numerical examples.

  10. Matching Dyadic Distributions to Channels

    OpenAIRE

    Böcherer, Georg; Mathar, Rudolf

    2010-01-01

    Many communication channels with discrete input have non-uniform capacity achieving probability mass functions (PMF). By parsing a stream of independent and equiprobable bits according to a full prefix-free code, a modu-lator can generate dyadic PMFs at the channel input. In this work, we show that for discrete memoryless channels and for memoryless discrete noiseless channels, searching for good dyadic input PMFs is equivalent to minimizing the Kullback-Leibler distance between a dyadic PMF ...

  11. Algorithmic complexity of quantum capacity

    Science.gov (United States)

    Oskouei, Samad Khabbazi; Mancini, Stefano

    2018-04-01

    We analyze the notion of quantum capacity from the perspective of algorithmic (descriptive) complexity. To this end, we resort to the concept of semi-computability in order to describe quantum states and quantum channel maps. We introduce algorithmic entropies (like algorithmic quantum coherent information) and derive relevant properties for them. Then we show that quantum capacity based on semi-computable concept equals the entropy rate of algorithmic coherent information, which in turn equals the standard quantum capacity. Thanks to this, we finally prove that the quantum capacity, for a given semi-computable channel, is limit computable.

  12. Channel Modeling

    Science.gov (United States)

    Schmitz, Arne; Schinnenburg, Marc; Gross, James; Aguiar, Ana

    For any communication system the Signal-to-Interference-plus-Noise-Ratio of the link is a fundamental metric. Recall (cf. Chapter 9) that the SINR is defined as the ratio between the received power of the signal of interest and the sum of all "disturbing" power sources (i.e. interference and noise). From information theory it is known that a higher SINR increases the maximum possible error-free transmission rate (referred to as Shannon capacity [417] of any communication system and vice versa). Conversely, the higher the SINR, the lower will be the bit error rate in practical systems. While one aspect of the SINR is the sum of all distracting power sources, another issue is the received power. This depends on the transmitted power, the used antennas, possibly on signal processing techniques and ultimately on the channel gain between transmitter and receiver.

  13. Understanding the 'Anorexic Voice' in Anorexia Nervosa.

    Science.gov (United States)

    Pugh, Matthew; Waller, Glenn

    2017-05-01

    In common with individuals experiencing a number of disorders, people with anorexia nervosa report experiencing an internal 'voice'. The anorexic voice comments on the individual's eating, weight and shape and instructs the individual to restrict or compensate. However, the core characteristics of the anorexic voice are not known. This study aimed to develop a parsimonious model of the voice characteristics that are related to key features of eating disorder pathology and to determine whether patients with anorexia nervosa fall into groups with different voice experiences. The participants were 49 women with full diagnoses of anorexia nervosa. Each completed validated measures of the power and nature of their voice experience and of their responses to the voice. Different voice characteristics were associated with current body mass index, duration of disorder and eating cognitions. Two subgroups emerged, with 'weaker' and 'stronger' voice experiences. Those with stronger voices were characterized by having more negative eating attitudes, more severe compensatory behaviours, a longer duration of illness and a greater likelihood of having the binge-purge subtype of anorexia nervosa. The findings indicate that the anorexic voice is an important element of the psychopathology of anorexia nervosa. Addressing the anorexic voice might be helpful in enhancing outcomes of treatments for anorexia nervosa, but that conclusion might apply only to patients with more severe eating psychopathology. Copyright © 2016 John Wiley & Sons, Ltd. Experiences of an internal 'anorexic voice' are common in anorexia nervosa. Clinicians should consider the role of the voice when formulating eating pathology in anorexia nervosa, including how individuals perceive and relate to that voice. Addressing the voice may be beneficial, particularly in more severe and enduring forms of anorexia nervosa. When working with the voice, clinicians should aim to address both the content of the voice and how

  14. Anti-voice adaptation suggests prototype-based coding of voice identity

    Directory of Open Access Journals (Sweden)

    Marianne eLatinus

    2011-07-01

    Full Text Available We used perceptual aftereffects induced by adaptation with anti-voice stimuli to investigate voice identity representations. Participants learned a set of voices then were tested on a voice identification task with vowel stimuli morphed between identities, after different conditions of adaptation. In Experiment 1, participants chose the identity opposite to the adapting anti-voice significantly more often than the other two identities (e.g., after being adapted to anti-A, they identified the average voice as A. In Experiment 2, participants showed a bias for identities opposite to the adaptor specifically for anti-voice, but not for non anti-voice adaptors. These results are strikingly similar to adaptation aftereffects observed for facial identity. They are compatible with a representation of individual voice identities in a multidimensional perceptual voice space referenced on a voice prototype.

  15. Optical voice encryption based on digital holography.

    Science.gov (United States)

    Rajput, Sudheesh K; Matoba, Osamu

    2017-11-15

    We propose an optical voice encryption scheme based on digital holography (DH). An off-axis DH is employed to acquire voice information by obtaining phase retardation occurring in the object wave due to sound wave propagation. The acquired hologram, including voice information, is encrypted using optical image encryption. The DH reconstruction and decryption with all the correct parameters can retrieve an original voice. The scheme has the capability to record the human voice in holograms and encrypt it directly. These aspects make the scheme suitable for other security applications and help to use the voice as a potential security tool. We present experimental and some part of simulation results.

  16. Activation of zero-error classical capacity in low-dimensional quantum systems

    Science.gov (United States)

    Park, Jeonghoon; Heo, Jun

    2018-06-01

    Channel capacities of quantum channels can be nonadditive even if one of two quantum channels has no channel capacity. We call this phenomenon activation of the channel capacity. In this paper, we show that when we use a quantum channel on a qubit system, only a noiseless qubit channel can generate the activation of the zero-error classical capacity. In particular, we show that the zero-error classical capacity of two quantum channels on qubit systems cannot be activated. Furthermore, we present a class of examples showing the activation of the zero-error classical capacity in low-dimensional systems.

  17. The Study of MSADQ/CDMA Protocol in Voice/Data Integration Packet Networks

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new packet medium access protocol, namely, minislot signalingaccess based on distributed queues(MSADQ/CDMA), is proposed in voice and data intergration CDMA networks. The MSADQ protocol is based on distributed queues and collision resolution algorithm. Through proper management of the PN codes, the number of random competition collision reduces greatly, the multiple access interference (MAI) decreases. It has several special access signaling channels to carry the voice and data access request. Each slot is devided into several control minislots (CMSs), in which the Data Terminals (DT) or Voice Terminals (VT) transmit their request. According to the voice and data traffic character, the signaling access structure is proposed. The code assign rules and queue managing rules are also proposed to ensure the QoS requirement of each traffic. Comparisions with other three protocol are developed by simulation, which shows that MSADQ/CDMA protocol occupies less PN codes, but still has very good performance.

  18. Quantum reading capacity

    International Nuclear Information System (INIS)

    Pirandola, Stefano; Braunstein, Samuel L; Lupo, Cosmo; Mancini, Stefano; Giovannetti, Vittorio

    2011-01-01

    The readout of a classical memory can be modelled as a problem of quantum channel discrimination, where a decoder retrieves information by distinguishing the different quantum channels encoded in each cell of the memory (Pirandola 2011 Phys. Rev. Lett. 106 090504). In the case of optical memories, such as CDs and DVDs, this discrimination involves lossy bosonic channels and can be remarkably boosted by the use of nonclassical light (quantum reading). Here we generalize these concepts by extending the model of memory from single-cell to multi-cell encoding. In general, information is stored in a block of cells by using a channel-codeword, i.e. a sequence of channels chosen according to a classical code. Correspondingly, the readout of data is realized by a process of ‘parallel’ channel discrimination, where the entire block of cells is probed simultaneously and decoded via an optimal collective measurement. In the limit of a large block we define the quantum reading capacity of the memory, quantifying the maximum number of readable bits per cell. This notion of capacity is nontrivial when we suitably constrain the physical resources of the decoder. For optical memories (encoding bosonic channels), such a constraint is energetic and corresponds to fixing the mean total number of photons per cell. In this case, we are able to prove a separation between the quantum reading capacity and the maximum information rate achievable by classical transmitters, i.e. arbitrary classical mixtures of coherent states. In fact, we can easily construct nonclassical transmitters that are able to outperform any classical transmitter, thus showing that the advantages of quantum reading persist in the optimal multi-cell scenario. (paper)

  19. Capacity Maximizing Constellations

    Science.gov (United States)

    Barsoum, Maged; Jones, Christopher

    2010-01-01

    Some non-traditional signal constellations have been proposed for transmission of data over the Additive White Gaussian Noise (AWGN) channel using such channel-capacity-approaching codes as low-density parity-check (LDPC) or turbo codes. Computational simulations have shown performance gains of more than 1 dB over traditional constellations. These gains could be translated to bandwidth- efficient communications, variously, over longer distances, using less power, or using smaller antennas. The proposed constellations have been used in a bit-interleaved coded modulation system employing state-ofthe-art LDPC codes. In computational simulations, these constellations were shown to afford performance gains over traditional constellations as predicted by the gap between the parallel decoding capacity of the constellations and the Gaussian capacity

  20. Mechanics of human voice production and control.

    Science.gov (United States)

    Zhang, Zhaoyan

    2016-10-01

    As the primary means of communication, voice plays an important role in daily life. Voice also conveys personal information such as social status, personal traits, and the emotional state of the speaker. Mechanically, voice production involves complex fluid-structure interaction within the glottis and its control by laryngeal muscle activation. An important goal of voice research is to establish a causal theory linking voice physiology and biomechanics to how speakers use and control voice to communicate meaning and personal information. Establishing such a causal theory has important implications for clinical voice management, voice training, and many speech technology applications. This paper provides a review of voice physiology and biomechanics, the physics of vocal fold vibration and sound production, and laryngeal muscular control of the fundamental frequency of voice, vocal intensity, and voice quality. Current efforts to develop mechanical and computational models of voice production are also critically reviewed. Finally, issues and future challenges in developing a causal theory of voice production and perception are discussed.

  1. The Voice as Computer Interface: A Look at Tomorrow's Technologies.

    Science.gov (United States)

    Lange, Holley R.

    1991-01-01

    Discussion of voice as the communications device for computer-human interaction focuses on voice recognition systems for use within a library environment. Voice technologies are described, including voice response and voice recognition; examples of voice systems in use in libraries are examined; and further possibilities, including use with…

  2. Channel CAT: A Tactical Link Analysis Tool

    National Research Council Canada - National Science Library

    Coleman, Michael

    1997-01-01

    .... This thesis produced an analysis tool, the Channel Capacity Analysis Tool (Channel CAT), designed to provide an automated tool for the analysis of design decisions in developing client-server software...

  3. Optimization of Communication in Noisy Quantum Channels

    National Research Council Canada - National Science Library

    Ruskai, Mary

    2002-01-01

    .... This project has been concerned with the analysis of mathematical models of noise for qubit channels, with the capacity of qubit channels used to transmit classical information, and with exchange...

  4. Quick Statistics about Voice, Speech, and Language

    Science.gov (United States)

    ... here Home » Health Info » Statistics and Epidemiology Quick Statistics About Voice, Speech, Language Voice, Speech, Language, and ... no 205. Hyattsville, MD: National Center for Health Statistics. 2015. Hoffman HJ, Li C-M, Losonczy K, ...

  5. English Voicing in Dimensional Theory*

    Science.gov (United States)

    Iverson, Gregory K.; Ahn, Sang-Cheol

    2007-01-01

    Assuming a framework of privative features, this paper interprets two apparently disparate phenomena in English phonology as structurally related: the lexically specific voicing of fricatives in plural nouns like wives or thieves and the prosodically governed “flapping” of medial /t/ (and /d/) in North American varieties, which we claim is itself not a rule per se, but rather a consequence of the laryngeal weakening of fortis /t/ in interaction with speech-rate determined segmental abbreviation. Taking as our point of departure the Dimensional Theory of laryngeal representation developed by Avery & Idsardi (2001), along with their assumption that English marks voiceless obstruents but not voiced ones (Iverson & Salmons 1995), we find that an unexpected connection between fricative voicing and coronal flapping emerges from the interplay of familiar phonemic and phonetic factors in the phonological system. PMID:18496590

  6. Audiovisual speech facilitates voice learning.

    Science.gov (United States)

    Sheffert, Sonya M; Olson, Elizabeth

    2004-02-01

    In this research, we investigated the effects of voice and face information on the perceptual learning of talkers and on long-term memory for spoken words. In the first phase, listeners were trained over several days to identify voices from words presented auditorily or audiovisually. The training data showed that visual information about speakers enhanced voice learning, revealing cross-modal connections in talker processing akin to those observed in speech processing. In the second phase, the listeners completed an auditory or audiovisual word recognition memory test in which equal numbers of words were spoken by familiar and unfamiliar talkers. The data showed that words presented by familiar talkers were more likely to be retrieved from episodic memory, regardless of modality. Together, these findings provide new information about the representational code underlying familiar talker recognition and the role of stimulus familiarity in episodic word recognition.

  7. Voices Falling Through the Air

    Directory of Open Access Journals (Sweden)

    Paul Elliman

    2012-11-01

    Full Text Available Where am I? Or as the young boy in Jules Verne’s Journey to the Centre of the Earth calls back to his distant-voiced companions: ‘Lost… in the most intense darkness.’ ‘Then I understood it,’ says the boy, Axel, ‘To make them hear me, all I had to do was to speak with my mouth close to the wall, which would serve to conduct my voice, as the wire conducts the electric fluid’ (Verne 1864. By timing their calls, the group of explorers work out that Axel is separated from them by a distance of four miles, held in a cavernous vertical gallery of smooth rock. Feeling his way down towards the others, the boy ends up falling, along with his voice, through the space. Losing consciousness he seems to give himself up to the space...

  8. A Comparative Survey of Adaptive Codec Solutions for VoIP over Multirate WLANs: A Capacity versus Quality Performance Trade-Off

    Directory of Open Access Journals (Sweden)

    Sfairopoulou A

    2011-01-01

    Full Text Available In multi-rate WLANs, users can suffer transmission rate changes due to the link adaptation mechanism. This results in a variable capacity channel, which is very hostile for VoIP and can cause serious quality of service (QoS degradation in all active calls. Various codec adaptation mechanisms have been proposed as a solution to this, as well as to solve congestion problems on WLAN environments. Here, these solutions are presented, categorized according to the adaptation policy and scenario they implement, and evaluated at call-level in terms of the resulting blocking and dropping probabilities, as well as the perceived voice quality. To define a common performance metric, a new index named VGoS-factor is presented, which, by combining these capacity and quality indicators, can provide an overall view of the capacity versus quality trade-off of the proposed mechanisms and consequently help in choosing the adequate policy for each scenario.

  9. DolphinAtack: Inaudible Voice Commands

    OpenAIRE

    Zhang, Guoming; Yan, Chen; Ji, Xiaoyu; Zhang, Taimin; Zhang, Tianchen; Xu, Wenyuan

    2017-01-01

    Speech recognition (SR) systems such as Siri or Google Now have become an increasingly popular human-computer interaction method, and have turned various systems into voice controllable systems(VCS). Prior work on attacking VCS shows that the hidden voice commands that are incomprehensible to people can control the systems. Hidden voice commands, though hidden, are nonetheless audible. In this work, we design a completely inaudible attack, DolphinAttack, that modulates voice commands on ultra...

  10. Speaker's voice as a memory cue.

    Science.gov (United States)

    Campeanu, Sandra; Craik, Fergus I M; Alain, Claude

    2015-02-01

    Speaker's voice occupies a central role as the cornerstone of auditory social interaction. Here, we review the evidence suggesting that speaker's voice constitutes an integral context cue in auditory memory. Investigation into the nature of voice representation as a memory cue is essential to understanding auditory memory and the neural correlates which underlie it. Evidence from behavioral and electrophysiological studies suggest that while specific voice reinstatement (i.e., same speaker) often appears to facilitate word memory even without attention to voice at study, the presence of a partial benefit of similar voices between study and test is less clear. In terms of explicit memory experiments utilizing unfamiliar voices, encoding methods appear to play a pivotal role. Voice congruency effects have been found when voice is specifically attended at study (i.e., when relatively shallow, perceptual encoding takes place). These behavioral findings coincide with neural indices of memory performance such as the parietal old/new recollection effect and the late right frontal effect. The former distinguishes between correctly identified old words and correctly identified new words, and reflects voice congruency only when voice is attended at study. Characterization of the latter likely depends upon voice memory, rather than word memory. There is also evidence to suggest that voice effects can be found in implicit memory paradigms. However, the presence of voice effects appears to depend greatly on the task employed. Using a word identification task, perceptual similarity between study and test conditions is, like for explicit memory tests, crucial. In addition, the type of noise employed appears to have a differential effect. While voice effects have been observed when white noise is used at both study and test, using multi-talker babble does not confer the same results. In terms of neuroimaging research modulations, characterization of an implicit memory effect

  11. Permanent Quadriplegia Following Replacement of Voice Prosthesis.

    Science.gov (United States)

    Ozturk, Kayhan; Erdur, Omer; Kibar, Ertugrul

    2016-11-01

    The authors presented a patient with quadriplegia caused by cervical spine abscess following voice prosthesis replacement. The authors present the first reported permanent quadriplegia patient caused by voice prosthesis replacement. The authors wanted to emphasize that life-threatening complications may be faced during the replacement of voice prosthesis. Care should be taken during the replacement of voice prosthesis and if some problems have been faced during the procedure patients must be followed closely.

  12. I like my voice better: self-enhancement bias in perceptions of voice attractiveness.

    Science.gov (United States)

    Hughes, Susan M; Harrison, Marissa A

    2013-01-01

    Previous research shows that the human voice can communicate a wealth of nonsemantic information; preferences for voices can predict health, fertility, and genetic quality of the speaker, and people often use voice attractiveness, in particular, to make these assessments of others. But it is not known what we think of the attractiveness of our own voices as others hear them. In this study eighty men and women rated the attractiveness of an array of voice recordings of different individuals and were not told that their own recorded voices were included in the presentation. Results showed that participants rated their own voices as sounding more attractive than others had rated their voices, and participants also rated their own voices as sounding more attractive than they had rated the voices of others. These findings suggest that people may engage in vocal implicit egotism, a form of self-enhancement.

  13. Does the speaker's voice quality influence children's performance on a language comprehension test?

    Science.gov (United States)

    Lyberg-Åhlander, Viveka; Haake, Magnus; Brännström, Jonas; Schötz, Susanne; Sahlén, Birgitta

    2015-02-01

    A small number of studies have explored children's perception of speakers' voice quality and its possible influence on language comprehension. The aim of this explorative study was to investigate the relationship between the examiner's voice quality, the child's performance on a digital version of a language comprehension test, the Test for Reception of Grammar (TROG-2), and two measures of cognitive functioning. The participants were (n = 86) mainstreamed 8-year old children with typical language development. Two groups of children (n = 41/45) were presented with the TROG-2 through recordings of one female speaker: one group was presented with a typical voice and the other with a simulated dysphonic voice. Significant associations were found between executive functioning and language comprehension. The results also showed that children listening to the dysphonic voice achieved significantly lower scores for more difficult sentences ("the man but not the horse jumps") and used more self-corrections on simpler sentences ("the girl is sitting"). Findings suggest that a dysphonic speaker's voice may force the child to allocate capacity to the processing of the voice signal at the expense of comprehension. The findings have implications for clinical and research settings where standardized language tests are used.

  14. Analyzing the mediated voice - a datasession

    DEFF Research Database (Denmark)

    Lawaetz, Anna

    Broadcasted voices are technologically manipulated. In order to achieve a certain autencity or sound of “reality” paradoxically the voices are filtered and trained in order to reach the listeners. This “mis-en-scene” is important knowledge when it comes to the development of a consistent method o...... of analysis of the mediated voice...

  15. Voices Not Heard: Voice-Use Profiles of Elementary Music Teachers, the Effects of Voice Amplification on Vocal Load, and Perceptions of Issues Surrounding Voice Use

    Science.gov (United States)

    Morrow, Sharon L.

    2009-01-01

    Teachers represent the largest group of occupational voice users and have voice-related problems at a rate of over twice that found in the general population. Among teachers, music teachers are roughly four times more likely than classroom teachers to develop voice-related problems. Although it has been established that music teachers use their…

  16. Interventions for preventing voice disorders in adults.

    Science.gov (United States)

    Ruotsalainen, J H; Sellman, J; Lehto, L; Jauhiainen, M; Verbeek, J H

    2007-10-17

    Poor voice quality due to a voice disorder can lead to a reduced quality of life. In occupations where voice use is substantial it can lead to periods of absence from work. To evaluate the effectiveness of interventions to prevent voice disorders in adults. We searched MEDLINE (PubMed, 1950 to 2006), EMBASE (1974 to 2006), CENTRAL (The Cochrane Library, Issue 2 2006), CINAHL (1983 to 2006), PsychINFO (1967 to 2006), Science Citation Index (1986 to 2006) and the Occupational Health databases OSH-ROM (to 2006). The date of the last search was 05/04/06. Randomised controlled clinical trials (RCTs) of interventions evaluating the effectiveness of treatments to prevent voice disorders in adults. For work-directed interventions interrupted time series and prospective cohort studies were also eligible. Two authors independently extracted data and assessed trial quality. Meta-analysis was performed where appropriate. We identified two randomised controlled trials including a total of 53 participants in intervention groups and 43 controls. One study was conducted with teachers and the other with student teachers. Both trials were poor quality. Interventions were grouped into 1) direct voice training, 2) indirect voice training and 3) direct and indirect voice training combined.1) Direct voice training: One study did not find a significant decrease of the Voice Handicap Index for direct voice training compared to no intervention.2) Indirect voice training: One study did not find a significant decrease of the Voice Handicap Index for indirect voice training when compared to no intervention.3) Direct and indirect voice training combined: One study did not find a decrease of the Voice Handicap Index for direct and indirect voice training combined when compared to no intervention. The same study did however find an improvement in maximum phonation time (Mean Difference -3.18 sec; 95 % CI -4.43 to -1.93) for direct and indirect voice training combined when compared to no

  17. AT89S52 Microcontroller Based Digital Compass With Voice Output

    Directory of Open Access Journals (Sweden)

    Fahmi Fardiyan Arief

    2008-04-01

    Full Text Available In this paper, the design of digital compass with voice output is described, so that the blind can also use it. The digital compass is designed based on up-graded conventional compass. In the axis direction of conventional compass be added a disc as source of wind direction information, and phototransistor as sensor. The digital compass system is designed, based on AT89S52 microcontroller, as control of all interfaces and read sensor. The LCD component is used as display and ISD 2590 IC as voice recorder. The IC can record with maximum capacity 90 seconds. The voices output of compass is divided into 8 direction from the north, southwest, west and the next. The result showed that the design of digital compass work as like conventional compass completely by voice feature.

  18. Objective Voice Parameters in Colombian School Workers with Healthy Voices

    Directory of Open Access Journals (Sweden)

    Lady Catherine Cantor Cutiva

    2015-09-01

    Full Text Available Objectives: To characterize the objective voice parameters among school workers, and to identi­fy associated factors of three objective voice parameters, namely fundamental frequency, sound pressure level and maximum phonation time. Materials and methods: We conducted a cross-sectional study among 116 Colombian teachers and 20 Colombian non-teachers. After signing the informed consent form, participants filled out a questionnaire. Then, a voice sample was recorded and evaluated perceptually by a speech therapist and by objective voice analysis with praat software. Short-term environmental measurements of sound level, temperature, humi­dity, and reverberation time were conducted during visits at the workplaces, such as classrooms and offices. Linear regression analysis was used to determine associations between individual and work-related factors and objective voice parameters. Results: Compared with men, women had higher fundamental frequency (201 Hz for teachers and 209 for non-teachers vs. 120 Hz for teachers and 127 for non-teachers and sound pressure level (82 dB vs. 80 dB, and shorter maximum phonation time (around 14 seconds vs. around 16 seconds. Female teachers younger than 50 years of age evidenced a significant tendency to speak with lower fundamental frequen­cy and shorter mpt compared with female teachers older than 50 years of age. Female teachers had significantly higher fundamental frequency (66 Hz, higher sound pressure level (2 dB and short phonation time (2 seconds than male teachers. Conclusion: Female teachers younger than 50 years of age had significantly lower F0 and shorter mpt compared with those older than 50 years of age. The multivariate analysis showed that gender was a much more important determinant of variations in F0, spl and mpt than age and teaching occupation. Objectively measured temperature also contributed to the changes on spl among school workers.

  19. Towards a Metalanguage Adequate to Linguistic Achievement in Post-Structuralism and English: Reflections on Voicing in the Writing of Secondary Students

    Science.gov (United States)

    Macken-Horarik, Mary; Morgan, Wendy

    2011-01-01

    This paper considers the development of voicing in the writing of secondary English students influenced by post-structuralist approaches to literature. It investigates students' growing capacity not only to voice their own responses to literature but also to relate these to a range of theoretical discourses. Drawing on systemic functional…

  20. Work-related voice disorder

    Directory of Open Access Journals (Sweden)

    Paulo Eduardo Przysiezny

    2015-04-01

    Full Text Available INTRODUCTION: Dysphonia is the main symptom of the disorders of oral communication. However, voice disorders also present with other symptoms such as difficulty in maintaining the voice (asthenia, vocal fatigue, variation in habitual vocal fundamental frequency, hoarseness, lack of vocal volume and projection, loss of vocal efficiency, and weakness when speaking. There are several proposals for the etiologic classification of dysphonia: functional, organofunctional, organic, and work-related voice disorder (WRVD.OBJECTIVE: To conduct a literature review on WRVD and on the current Brazilian labor legislation.METHODS: This was a review article with bibliographical research conducted on the PubMed and Bireme databases, using the terms "work-related voice disorder", "occupational dysphonia", "dysphonia and labor legislation", and a review of labor and social security relevant laws.CONCLUSION: WRVD is a situation that frequently is listed as a reason for work absenteeism, functional rehabilitation, or for prolonged absence from work. Currently, forensic physicians have no comparative parameters to help with the analysis of vocal disorders. In certain situations WRVD may cause, work disability. This disorder may be labor-related, or be an adjuvant factor to work-related diseases.

  1. FILTWAM and Voice Emotion Recognition

    NARCIS (Netherlands)

    Bahreini, Kiavash; Nadolski, Rob; Westera, Wim

    2014-01-01

    This paper introduces the voice emotion recognition part of our framework for improving learning through webcams and microphones (FILTWAM). This framework enables multimodal emotion recognition of learners during game-based learning. The main goal of this study is to validate the use of microphone

  2. Playful Interaction with Voice Sensing Modular Robots

    DEFF Research Database (Denmark)

    Heesche, Bjarke; MacDonald, Ewen; Fogh, Rune

    2013-01-01

    This paper describes a voice sensor, suitable for modular robotic systems, which estimates the energy and fundamental frequency, F0, of the user’s voice. Through a number of example applications and tests with children, we observe how the voice sensor facilitates playful interaction between child...... children and two different robot configurations. In future work, we will investigate if such a system can motivate children to improve voice control and explore how to extend the sensor to detect emotions in the user’s voice....

  3. Quantum communication under channel uncertainty

    International Nuclear Information System (INIS)

    Noetzel, Janis Christian Gregor

    2012-01-01

    This work contains results concerning transmission of entanglement and subspaces as well as generation of entanglement in the limit of arbitrary many uses of compound- and arbitrarily varying quantum channels (CQC, AVQC). In both cases, the channel is described by a set of memoryless channels. Only forward communication between one sender and one receiver is allowed. A code is said to be ''good'' only, if it is ''good'' for every channel out of the set. Both settings describe a scenario, in which sender and receiver have only limited channel knowledge. For different amounts of information about the channel available to sender or receiver, coding theorems are proven for the CQC. For the AVQC, both deterministic and randomised coding schemes are considered. Coding theorems are proven, as well as a quantum analogue of the Ahlswede-dichotomy. The connection to zero-error capacities of stationary memoryless quantum channels is investigated. The notion of symmetrisability is defined and used for both classes of channels.

  4. Is children's listening effort in background noise influenced by the speaker's voice quality?

    Science.gov (United States)

    Sahlén, Birgitta; Haake, Magnus; von Lochow, Heike; Holm, Lucas; Kastberg, Tobias; Brännström, K Jonas; Lyberg-Åhlander, Viveka

    2018-07-01

    The present study aims at exploring the influence of voice quality on listening effort in children performing a language comprehension test with sentences of increasing difficulty. Listening effort is explored in relation to gender ( = cisgender). The study has a between-groups design. Ninety-three mainstreamed children aged 8;2 to 9;3 with typical language development participated. The children were randomly assigned to two groups (n = 46/47) with equal allocation of boys and girls and for the analysis to four groups depending of gender and voice condition. Working memory capacity and executive functions were tested in quiet. A digital version of a language comprehension test (the TROG-2) was used to measure the effect of voice quality on listening effort, measured as response time in a forced-choice paradigm. The groups listened to sentences through recordings of the same female voice, one group with a typical voice and one with a dysphonic voice, both in competing multi-talker babble noise. Response times were logged after a time buffer between the sentence-ending and indication of response. There was a significant increase in response times with increased task difficulty and response times between the two voice conditions differed significantly. The girls in the dysphonic condition were slower with increasing task difficulty. A dysphonic voice clearly adds to the noise burden and listening effort is greater in girls than in boys when the teacher speaks with dysphonic voice in a noisy background. These findings might mirror gender differences as for coping strategies in challenging contexts and have important implications for education.

  5. VOICE QUALITY BEFORE AND AFTER THYROIDECTOMY

    Directory of Open Access Journals (Sweden)

    Dora CVELBAR

    2016-04-01

    Full Text Available Introduction: Voice disorders are a well-known complication which is often associated with thyroid gland diseases and because voice is still the basic mean of communication it is very important to maintain its quality healthy. Objectives: The aim of this study referred to questions whether there is a statistically significant difference between results of voice self-assessment, perceptual voice assessment and acoustic voice analysis before and after thyroidectomy and whether there are statistically significant correlations between variables of voice self-assessment, perceptual assessment and acoustic analysis before and after thyroidectomy. Methods: This scientific research included 12 participants aged between 41 and 76. Voice self-assessment was conducted with the help of Croatian version of Voice Handicap Index (VHI. Recorded reading samples were used for perceptual assessment and later evaluated by two clinical speech and language therapists. Recorded samples of phonation were used for acoustic analysis which was conducted with the help of acoustic program Praat. All of the data was processed through descriptive statistics and nonparametric statistical methods. Results: Results showed that there are statistically significant differences between results of voice self-assessments and results of acoustic analysis before and after thyroidectomy. Statistically significant correlations were found between variables of perceptual assessment and acoustic analysis. Conclusion: Obtained results indicate the importance of multidimensional, preoperative and postoperative assessment. This kind of assessment allows the clinician to describe all of the voice features and provides appropriate recommendation for further rehabilitation to the patient in order to optimize voice outcomes.

  6. Application of computer voice input/output

    International Nuclear Information System (INIS)

    Ford, W.; Shirk, D.G.

    1981-01-01

    The advent of microprocessors and other large-scale integration (LSI) circuits is making voice input and output for computers and instruments practical; specialized LSI chips for speech processing are appearing on the market. Voice can be used to input data or to issue instrument commands; this allows the operator to engage in other tasks, move about, and to use standard data entry systems. Voice synthesizers can generate audible, easily understood instructions. Using voice characteristics, a control system can verify speaker identity for security purposes. Two simple voice-controlled systems have been designed at Los Alamos for nuclear safeguards applicaations. Each can easily be expanded as time allows. The first system is for instrument control that accepts voice commands and issues audible operator prompts. The second system is for access control. The speaker's voice is used to verify his identity and to actuate external devices

  7. The development of the Spanish verb ir into auxiliary of voice

    DEFF Research Database (Denmark)

    Vinther, Thora

    2005-01-01

    spanish, syntax, grammaticalisation, past participle, passive voice, middle voice, language development......spanish, syntax, grammaticalisation, past participle, passive voice, middle voice, language development...

  8. Robotics control using isolated word recognition of voice input

    Science.gov (United States)

    Weiner, J. M.

    1977-01-01

    A speech input/output system is presented that can be used to communicate with a task oriented system. Human speech commands and synthesized voice output extend conventional information exchange capabilities between man and machine by utilizing audio input and output channels. The speech input facility is comprised of a hardware feature extractor and a microprocessor implemented isolated word or phrase recognition system. The recognizer offers a medium sized (100 commands), syntactically constrained vocabulary, and exhibits close to real time performance. The major portion of the recognition processing required is accomplished through software, minimizing the complexity of the hardware feature extractor.

  9. Foetal response to music and voice.

    Science.gov (United States)

    Al-Qahtani, Noura H

    2005-10-01

    To examine whether prenatal exposure to music and voice alters foetal behaviour and whether foetal response to music differs from human voice. A prospective observational study was conducted in 20 normal term pregnant mothers. Ten foetuses were exposed to music and voice for 15 s at different sound pressure levels to find out the optimal setting for the auditory stimulation. Music, voice and sham were played to another 10 foetuses via a headphone on the maternal abdomen. The sound pressure level was 105 db and 94 db for music and voice, respectively. Computerised assessment of foetal heart rate and activity were recorded. 90 actocardiograms were obtained for the whole group. One way anova followed by posthoc (Student-Newman-Keuls method) analysis was used to find if there is significant difference in foetal response to music and voice versus sham. Foetuses responded with heart rate acceleration and motor response to both music and voice. This was statistically significant compared to sham. There was no significant difference between the foetal heart rate acceleration to music and voice. Prenatal exposure to music and voice alters the foetal behaviour. No difference was detected in foetal response to music and voice.

  10. Voice disorders in mucosal leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Ana Cristina Nunes Ruas

    Full Text Available INTRODUCTION: Leishmaniasis is considered as one of the six most important infectious diseases because of its high detection coefficient and ability to produce deformities. In most cases, mucosal leishmaniasis (ML occurs as a consequence of cutaneous leishmaniasis. If left untreated, mucosal lesions can leave sequelae, interfering in the swallowing, breathing, voice and speech processes and requiring rehabilitation. OBJECTIVE: To describe the anatomical characteristics and voice quality of ML patients. MATERIALS AND METHODS: A descriptive transversal study was conducted in a cohort of ML patients treated at the Laboratory for Leishmaniasis Surveillance of the Evandro Chagas National Institute of Infectious Diseases-Fiocruz, between 2010 and 2013. The patients were submitted to otorhinolaryngologic clinical examination by endoscopy of the upper airways and digestive tract and to speech-language assessment through directed anamnesis, auditory perception, phonation times and vocal acoustic analysis. The variables of interest were epidemiologic (sex and age and clinic (lesion location, associated symptoms and voice quality. RESULTS: 26 patients under ML treatment and monitored by speech therapists were studied. 21 (81% were male and five (19% female, with ages ranging from 15 to 78 years (54.5+15.0 years. The lesions were distributed in the following structures 88.5% nasal, 38.5% oral, 34.6% pharyngeal and 19.2% laryngeal, with some patients presenting lesions in more than one anatomic site. The main complaint was nasal obstruction (73.1%, followed by dysphonia (38.5%, odynophagia (30.8% and dysphagia (26.9%. 23 patients (84.6% presented voice quality perturbations. Dysphonia was significantly associated to lesions in the larynx, pharynx and oral cavity. CONCLUSION: We observed that vocal quality perturbations are frequent in patients with mucosal leishmaniasis, even without laryngeal lesions; they are probably associated to disorders of some

  11. Sparking Passion: Engaging Student Voice through Project-Based Learning in Learning Communities

    Science.gov (United States)

    Ball, Christy L.

    2016-01-01

    How do we confront entrenched educational practices in higher education that lead to student demotivation, poor retention, and low persistence? This article argues that project-based learning that situates student voice and capacity at the center of culturally-responsive curriculum has the potential to spark student passion for problem-solving…

  12. Voice congruency facilitates word recognition.

    Directory of Open Access Journals (Sweden)

    Sandra Campeanu

    Full Text Available Behavioral studies of spoken word memory have shown that context congruency facilitates both word and source recognition, though the level at which context exerts its influence remains equivocal. We measured event-related potentials (ERPs while participants performed both types of recognition task with words spoken in four voices. Two voice parameters (i.e., gender and accent varied between speakers, with the possibility that none, one or two of these parameters was congruent between study and test. Results indicated that reinstating the study voice at test facilitated both word and source recognition, compared to similar or no context congruency at test. Behavioral effects were paralleled by two ERP modulations. First, in the word recognition test, the left parietal old/new effect showed a positive deflection reflective of context congruency between study and test words. Namely, the same speaker condition provided the most positive deflection of all correctly identified old words. In the source recognition test, a right frontal positivity was found for the same speaker condition compared to the different speaker conditions, regardless of response success. Taken together, the results of this study suggest that the benefit of context congruency is reflected behaviorally and in ERP modulations traditionally associated with recognition memory.

  13. Voice congruency facilitates word recognition.

    Science.gov (United States)

    Campeanu, Sandra; Craik, Fergus I M; Alain, Claude

    2013-01-01

    Behavioral studies of spoken word memory have shown that context congruency facilitates both word and source recognition, though the level at which context exerts its influence remains equivocal. We measured event-related potentials (ERPs) while participants performed both types of recognition task with words spoken in four voices. Two voice parameters (i.e., gender and accent) varied between speakers, with the possibility that none, one or two of these parameters was congruent between study and test. Results indicated that reinstating the study voice at test facilitated both word and source recognition, compared to similar or no context congruency at test. Behavioral effects were paralleled by two ERP modulations. First, in the word recognition test, the left parietal old/new effect showed a positive deflection reflective of context congruency between study and test words. Namely, the same speaker condition provided the most positive deflection of all correctly identified old words. In the source recognition test, a right frontal positivity was found for the same speaker condition compared to the different speaker conditions, regardless of response success. Taken together, the results of this study suggest that the benefit of context congruency is reflected behaviorally and in ERP modulations traditionally associated with recognition memory.

  14. Impact of dynamic rate coding aspects of mobile phone networks on forensic voice comparison.

    Science.gov (United States)

    Alzqhoul, Esam A S; Nair, Balamurali B T; Guillemin, Bernard J

    2015-09-01

    Previous studies have shown that landline and mobile phone networks are different in their ways of handling the speech signal, and therefore in their impact on it. But the same is also true of the different networks within the mobile phone arena. There are two major mobile phone technologies currently in use today, namely the global system for mobile communications (GSM) and code division multiple access (CDMA) and these are fundamentally different in their design. For example, the quality of the coded speech in the GSM network is a function of channel quality, whereas in the CDMA network it is determined by channel capacity (i.e., the number of users sharing a cell site). This paper examines the impact on the speech signal of a key feature of these networks, namely dynamic rate coding, and its subsequent impact on the task of likelihood-ratio-based forensic voice comparison (FVC). Surprisingly, both FVC accuracy and precision are found to be better for both GSM- and CDMA-coded speech than for uncoded. Intuitively one expects FVC accuracy to increase with increasing coded speech quality. This trend is shown to occur for the CDMA network, but, surprisingly, not for the GSM network. Further, in respect to comparisons between these two networks, FVC accuracy for CDMA-coded speech is shown to be slightly better than for GSM-coded speech, particularly when the coded-speech quality is high, but in terms of FVC precision the two networks are shown to be very similar. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

  15. [Assessment of voice acoustic parameters in female teachers with diagnosed occupational voice disorders].

    Science.gov (United States)

    Niebudek-Bogusz, Ewa; Fiszer, Marta; Sliwińska-Kowalska, Mariola

    2005-01-01

    Laryngovideostroboscopy is the method most frequently used in the assessment of voice disorders. However, the employment of quantitative methods, such as voice acoustic analysis, is essential for evaluating the effectiveness of prophylactic and therapeutic activities as well as for objective medical certification of larynx pathologies. The aim of this study was to examine voice acoustic parameters in female teachers with occupational voice diseases. Acoustic analysis (IRIS software) was performed in 66 female teachers, including 35 teachers with occupational voice diseases and 31 with functional dysphonia. The teachers with occupational voice diseases presented the lower average fundamental frequency (193 Hz) compared to the group with functional dysphonia (209 Hz) and to the normative value (236 Hz), whereas other acoustic parameters did not differ significantly in both groups. Voice acoustic analysis, when applied separately from vocal loading, cannot be used as a testing method to verify the diagnosis of occupational voice disorders.

  16. Integrating cues of social interest and voice pitch in men's preferences for women's voices

    OpenAIRE

    Jones, Benedict C; Feinberg, David R; DeBruine, Lisa M; Little, Anthony C; Vukovic, Jovana

    2008-01-01

    Most previous studies of vocal attractiveness have focused on preferences for physical characteristics of voices such as pitch. Here we examine the content of vocalizations in interaction with such physical traits, finding that vocal cues of social interest modulate the strength of men's preferences for raised pitch in women's voices. Men showed stronger preferences for raised pitch when judging the voices of women who appeared interested in the listener than when judging the voices of women ...

  17. ACHIEVING THE NATURAL VOICE: THE ANALYSIS OF THE LINKLATER METHOD FROM A TRAINING PERSPECTİVE–

    Directory of Open Access Journals (Sweden)

    Asli YILMAZ DAVUTOGLU

    2015-09-01

    Full Text Available In the 20th century, one of the most widespread of the voice training methods that start with the concepts “natural voice” and “the rediscovery of voice” is the Linklater Method. The primary target group of this method is actors. With its exercises designed for the "reconstruction of the body, the voice and the mind", this method aims at utilizing the innate voice capacity. As a multidisciplinary method fostered by many a scientific discipline and Eastern teaching, Linklater method comes with a language that is imbued with sophisticated and metaphorical expressions, scientific terminology and acting jargon, which makes the method prone to false and/or superficial references. The target of the present study is to explicate with a “trainer's perspective” the fundamental concepts and propositions of the Linklater Method, most notably the “natural voice”. Also, the present study aims at analysing the relation between the basic practices of the method and recent scientific data, thus examining the mental substructure these practices are based on and their physical/technical goals. In this direction, the present study involves the adopting of a general framework with respect to the inclinations and scientific sources of voice training in the 20th century that affected Linklater's propositions, a simplified summarisation of the neuro-anatomic process producing the voice, the selection of exercises on which the principles and goals of the method can be seen concretely and the grouping of these exercises under titles pertaining to the four basic steps of voice production. In the conclusion part of the study, it is argued that this method, despite being regarded as “alternative/experimental” when compared to conventional methods in Turkey, is one of the mainstream methods in contemporary voice training and that it is shaped through a multi-purpose system whose aim is not only voice training but also to develop the creativity and

  18. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    the probability of conflicts and the minimum headway times into account. The last method analyzes how optimal platform tracks are used by examining the arrival and departure pattern of the trains. The developed methods can either be used separately to analyze specific characteristics of the capacity of a station......Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore...... for platform tracks and the probability that arriving trains will not get a platform track immediately at arrival. The third method is a scalable method that analyzes the conflicts in the switch zone(s). In its simplest stage, the method just analyzes the track layout while the more advanced stages also take...

  19. Can blind persons accurately assess body size from the voice?

    Science.gov (United States)

    Pisanski, Katarzyna; Oleszkiewicz, Anna; Sorokowska, Agnieszka

    2016-04-01

    Vocal tract resonances provide reliable information about a speaker's body size that human listeners use for biosocial judgements as well as speech recognition. Although humans can accurately assess men's relative body size from the voice alone, how this ability is acquired remains unknown. In this study, we test the prediction that accurate voice-based size estimation is possible without prior audiovisual experience linking low frequencies to large bodies. Ninety-one healthy congenitally or early blind, late blind and sighted adults (aged 20-65) participated in the study. On the basis of vowel sounds alone, participants assessed the relative body sizes of male pairs of varying heights. Accuracy of voice-based body size assessments significantly exceeded chance and did not differ among participants who were sighted, or congenitally blind or who had lost their sight later in life. Accuracy increased significantly with relative differences in physical height between men, suggesting that both blind and sighted participants used reliable vocal cues to size (i.e. vocal tract resonances). Our findings demonstrate that prior visual experience is not necessary for accurate body size estimation. This capacity, integral to both nonverbal communication and speech perception, may be present at birth or may generalize from broader cross-modal correspondences. © 2016 The Author(s).

  20. Voice Onset Time in Azerbaijani Consonants

    Directory of Open Access Journals (Sweden)

    Ali Jahan

    2009-10-01

    Full Text Available Objective: Voice onset time is known to be cue for the distinction between voiced and voiceless stops and it can be used to describe or categorize a range of developmental, neuromotor and linguistic disorders. The aim of this study is determination of standard values of voice onset time for Azerbaijani language (Tabriz dialect. Materials & Methods: In this description-analytical study, 30 Azeris persons whom were selected conveniently by simple selection, uttered 46 monosyllabic words initiating with 6 Azerbaijani stops twice. Using Praat software, the voice onset time values were analyzed by waveform and wideband spectrogram in milliseconds. Vowel effect, sex differences and the effect of place of articulation on VOT, were evaluated and data were analyzed by one-way ANOVA test. Results: There was no significant difference in voice onset time between male and female Azeris speakers (P<0.05. Vowel and place of articulation had significant correlation with voice onset time (P<0.001. Voice onset time values for /b/, /p/, /d/, /t/, /g/, /k/, and [c], [ɟ] allophones were 10.64, 86.88, 13.35, 87.09, 26.25, 100.62, 131.19, 63.18 mili second, respectively. Conclusion: Voice onset time values are the same for Azerbaijani men and women. However, like many other languages, back and high vowels and back place of articulation lengthen VOT. Also, voiceless stops are aspirated in this language and voiced stops have positive VOT values.

  1. Singing Voice Analysis, Synthesis, and Modeling

    Science.gov (United States)

    Kim, Youngmoo E.

    The singing voice is the oldest musical instrument, but its versatility and emotional power are unmatched. Through the combination of music, lyrics, and expression, the voice is able to affect us in ways that no other instrument can. The fact that vocal music is prevalent in almost all cultures is indicative of its innate appeal to the human aesthetic. Singing also permeates most genres of music, attesting to the wide range of sounds the human voice is capable of producing. As listeners we are naturally drawn to the sound of the human voice, and, when present, it immediately becomes the focus of our attention.

  2. Familiarity and Voice Representation: From Acoustic-Based Representation to Voice Averages

    Directory of Open Access Journals (Sweden)

    Maureen Fontaine

    2017-07-01

    Full Text Available The ability to recognize an individual from their voice is a widespread ability with a long evolutionary history. Yet, the perceptual representation of familiar voices is ill-defined. In two experiments, we explored the neuropsychological processes involved in the perception of voice identity. We specifically explored the hypothesis that familiar voices (trained-to-familiar (Experiment 1, and famous voices (Experiment 2 are represented as a whole complex pattern, well approximated by the average of multiple utterances produced by a single speaker. In experiment 1, participants learned three voices over several sessions, and performed a three-alternative forced-choice identification task on original voice samples and several “speaker averages,” created by morphing across varying numbers of different vowels (e.g., [a] and [i] produced by the same speaker. In experiment 2, the same participants performed the same task on voice samples produced by familiar speakers. The two experiments showed that for famous voices, but not for trained-to-familiar voices, identification performance increased and response times decreased as a function of the number of utterances in the averages. This study sheds light on the perceptual representation of familiar voices, and demonstrates the power of average in recognizing familiar voices. The speaker average captures the unique characteristics of a speaker, and thus retains the information essential for recognition; it acts as a prototype of the speaker.

  3. "Voice Forum" The Human Voice as Primary Instrument in Music Therapy

    DEFF Research Database (Denmark)

    Pedersen, Inge Nygaard; Storm, Sanne

    2009-01-01

    Aspects will be drawn on the human voice as tool for embodying our psychological and physiological state, and attempting integration of feelings. Presentations and dialogues on different methods and techniques in "Therapy related body-and voice work.", as well as the human voice as a tool for non...

  4. Universal communication part II: channels with memory

    OpenAIRE

    Lomnitz, Yuval; Feder, Meir

    2012-01-01

    Consider communication over a channel whose probabilistic model is completely unknown vector-wise and is not assumed to be stationary. Communication over such channels is challenging because knowing the past does not indicate anything about the future. The existence of reliable feedback and common randomness is assumed. In a previous paper it was shown that the Shannon capacity cannot be attained, in general, if the channel is not known. An alternative notion of "capacity" was defined, as the...

  5. Test-retest reliability for aerodynamic measures of voice.

    Science.gov (United States)

    Awan, Shaheen N; Novaleski, Carolyn K; Yingling, Julie R

    2013-11-01

    The purpose of this study was to investigate the intrasubject reliability of aerodynamic characteristics of the voice within typical/normal speakers across testing sessions using the Phonatory Aerodynamic System (PAS 6600; KayPENTAX, Montvale, NJ). Participants were 60 healthy young adults (30 males and 30 females) between the ages 18 and 31 years with perceptually typical voice. Participants were tested using the PAS 6600 (Phonatory Aerodynamic System) on two separate days with approximately 1 week between each session at approximately the same time of day. Four PAS protocols were conducted (vital capacity, maximum sustained phonation, comfortable sustained phonation, and voicing efficiency) and measures of expiratory volume, maximum phonation time, mean expiratory airflow (during vowel production) and target airflow (obtained via syllable repetition), peak air pressure, aerodynamic power, aerodynamic resistance, and aerodynamic efficiency were obtained during each testing session. Associated acoustic measures of vocal intensity and frequency were also collected. All phonations were elicited at comfortable pitch and loudness. All aerodynamic and associated variables evaluated in this study showed useable test-retest reliability (ie, intraclass correlation coefficients [ICCs] ≥ 0.60). A high degree of mean test-retest reliability was found across all subjects for aerodynamic and associated acoustic measurements of vital capacity, maximum sustained phonation, glottal resistance, and vocal intensity (all with ICCs > 0.75). Although strong ICCs were observed for measures of glottal power and mean expiratory airflow in males, weaker overall results for these measures (ICC range: 0.60-0.67) were observed in females subjects and sizable coefficients of variation were observed for measures of power, resistance, and efficiency in both men and women. Differences in degree of reliability from measure to measure were revealed in greater detail using methods such as ICCs and

  6. Clinical voice analysis of Carnatic singers.

    Science.gov (United States)

    Arunachalam, Ravikumar; Boominathan, Prakash; Mahalingam, Shenbagavalli

    2014-01-01

    Carnatic singing is a classical South Indian style of music that involves rigorous training to produce an "open throated" loud, predominantly low-pitched singing, embedded with vocal nuances in higher pitches. Voice problems in singers are not uncommon. The objective was to report the nature of voice problems and apply a routine protocol to assess the voice. Forty-five trained performing singers (females: 36 and males: 9) who reported to a tertiary care hospital with voice problems underwent voice assessment. The study analyzed their problems and the clinical findings. Voice change, difficulty in singing higher pitches, and voice fatigue were major complaints. Most of the singers suffered laryngopharyngeal reflux that coexisted with muscle tension dysphonia and chronic laryngitis. Speaking voices were rated predominantly as "moderate deviation" on GRBAS (Grade, Rough, Breathy, Asthenia, and Strain). Maximum phonation time ranged from 4 to 29 seconds (females: 10.2, standard deviation [SD]: 5.28 and males: 15.7, SD: 5.79). Singing frequency range was reduced (females: 21.3 Semitones and males: 23.99 Semitones). Dysphonia severity index (DSI) scores ranged from -3.5 to 4.91 (females: 0.075 and males: 0.64). Singing frequency range and DSI did not show significant difference between sex and across clinical diagnosis. Self-perception using voice disorder outcome profile revealed overall severity score of 5.1 (SD: 2.7). Findings are discussed from a clinical intervention perspective. Study highlighted the nature of voice problems (hyperfunctional) and required modifications in assessment protocol for Carnatic singers. Need for regular assessments and vocal hygiene education to maintain good vocal health are emphasized as outcomes. Copyright © 2014 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  7. Associations between the Transsexual Voice Questionnaire (TVQMtF ) and self-report of voice femininity and acoustic voice measures.

    Science.gov (United States)

    Dacakis, Georgia; Oates, Jennifer; Douglas, Jacinta

    2017-11-01

    The Transsexual Voice Questionnaire (TVQ MtF ) was designed to capture the voice-related perceptions of individuals whose gender identity as female is the opposite of their birth-assigned gender (MtF women). Evaluation of the psychometric properties of the TVQ MtF is ongoing. To investigate associations between TVQ MtF scores and (1) self-perceptions of voice femininity and (2) acoustic parameters of voice pitch and voice quality in order to evaluate further the validity of the TVQ MtF . A strong correlation between TVQ MtF scores and self-ratings of voice femininity was predicted, but no association between TVQ MtF scores and acoustic measures of voice pitch and quality was proposed. Participants were 148 MtF women (mean age 48.14 years) recruited from the La Trobe Communication Clinic and the clinics of three doctors specializing in transgender health. All participants completed the TVQ MtF and 34 of these participants also provided a voice sample for acoustic analysis. Pearson product-moment correlation analysis was conducted to examine the associations between TVQ MtF scores and (1) self-perceptions of voice femininity and (2) acoustic measures of F0, jitter (%), shimmer (dB) and harmonic-to-noise ratio (HNR). Strong negative correlations between the participants' perceptions of their voice femininity and the TVQ MtF scores demonstrated that for this group of MtF women a low self-rating of voice femininity was associated with more frequent negative voice-related experiences. This association was strongest with the vocal-functioning component of the TVQ MtF . These strong correlations and high levels of shared variance between the TVQ MtF and a measure of a related construct provides evidence for the convergent validity of the TVQ MtF . The absence of significant correlations between the TVQ MtF and the acoustic data is consistent with the equivocal findings of earlier research. This finding indicates that these two measures assess different aspects of the voice

  8. Sound induced activity in voice sensitive cortex predicts voice memory ability

    Directory of Open Access Journals (Sweden)

    Rebecca eWatson

    2012-04-01

    Full Text Available The ‘temporal voice areas’ (TVAs (Belin et al., 2000 of the human brain show greater neuronal activity in response to human voices than to other categories of nonvocal sounds. However, a direct link between TVA activity and voice perceptionbehaviour has not yet been established. Here we show that a functional magnetic resonance imaging (fMRI measure of activity in the TVAs predicts individual performance at a separately administered voice memory test. This relation holds whengeneral sound memory ability is taken into account. These findings provide the first evidence that the TVAs are specifically involved in voice cognition.

  9. Voices from Around the Globe

    Directory of Open Access Journals (Sweden)

    Birgit Schreiber

    2017-07-01

    Full Text Available JSAA has been seeking to provide an opportunity for Student Affairs professionals and higher education scholars from around the globe to share their research and experiences of student services and student affairs programmes from their respective regional and institutional contexts. This has been given a specific platform with the guest-edited issue “Voices from Around the Globe” which is the result of a collaboration with the International Association of Student Affairs and Services (IASAS, and particularly with the guest editors, Kathleen Callahan and Chinedu Mba.

  10. Voice Disorders: Etiology and Diagnosis.

    Science.gov (United States)

    Martins, Regina Helena Garcia; do Amaral, Henrique Abrantes; Tavares, Elaine Lara Mendes; Martins, Maira Garcia; Gonçalves, Tatiana Maria; Dias, Norimar Hernandes

    2016-11-01

    Voice disorders affect adults and children and have different causes in different age groups. The aim of the study is to present the etiology and diagnosis dysphonia in a large population of patients with this voice disorder.for dysphonia of a large population of dysphonic patients. We evaluated 2019 patients with dysphonia who attended the Voice Disease ambulatories of a university hospital. Parameters assessed were age, gender, profession, associated symptoms, smoking, and videolaryngoscopy diagnoses. Of the 2019 patients with dysphonia who were included in this study, 786 were male (38.93%) and 1233 were female (61.07). The age groups were as follows: 1-6 years (n = 100); 7-12 years (n = 187); 13-18 years (n = 92); 19-39 years (n = 494); 41-60 years (n = 811); and >60 years (n = 335). Symptoms associated with dysphonia were vocal overuse (n = 677), gastroesophageal symptoms (n = 535), and nasosinusal symptoms (n = 497). The predominant professions of the patients were domestic workers, students, and teachers. Smoking was reported by 13.6% patients. With regard to the etiology of dysphonia, in children (1-18 years old), nodules (n = 225; 59.3%), cysts (n = 39; 10.3%), and acute laryngitis (n = 26; 6.8%) prevailed. In adults (19-60 years old), functional dysphonia (n = 268; 20.5%), acid laryngitis (n = 164; 12.5%), and vocal polyps (n = 156; 12%) predominated. In patients older than 60 years, presbyphonia (n = 89; 26.5%), functional dysphonia (n = 59; 17.6%), and Reinke's edema (n = 48; 14%) predominated. In this population of 2019 patients with dysphonia, adults and women were predominant. Dysphonia had different etiologies in the age groups studied. Nodules and cysts were predominant in children, functional dysphonia and reflux in adults, and presbyphonia and Reinke's edema in the elderly. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  11. From Out of Our Voices

    Directory of Open Access Journals (Sweden)

    Evangelia Papanikolaou

    2010-01-01

    Full Text Available Note from the interviewer: Diane Austin's new book “The Theory and Practice of Vocal Psychotherapy: Songs of the Self” (2008 which was published recently, has been an excellent opportunity to learn more about the use of voice in therapy, its clinical applications and its enormous possibilities that offers within a psychotherapeutic setting. This interview focuses on introducing some of these aspects based on Austin’s work, and on exploring her background, motivations and considerations towards this pioneer music-therapeutic approach. The interview has been edited by Diane Austin and Evangelia Papanikolaou and took place via a series of emails, dated from September to December 2009.

  12. Muscular tension and body posture in relation to voice handicap and voice quality in teachers with persistent voice complaints.

    Science.gov (United States)

    Kooijman, P G C; de Jong, F I C R S; Oudes, M J; Huinck, W; van Acht, H; Graamans, K

    2005-01-01

    The aim of this study was to investigate the relationship between extrinsic laryngeal muscular hypertonicity and deviant body posture on the one hand and voice handicap and voice quality on the other hand in teachers with persistent voice complaints and a history of voice-related absenteeism. The study group consisted of 25 female teachers. A voice therapist assessed extrinsic laryngeal muscular tension and a physical therapist assessed body posture. The assessed parameters were clustered in categories. The parameters in the different categories represent the same function. Further a tension/posture index was created, which is the summation of the different parameters. The different parameters and the index were related to the Voice Handicap Index (VHI) and the Dysphonia Severity Index (DSI). The scores of the VHI and the individual parameters differ significantly except for the posterior weight bearing and tension of the sternocleidomastoid muscle. There was also a significant difference between the individual parameters and the DSI, except for tension of the cricothyroid muscle and posterior weight bearing. The score of the tension/posture index correlates significantly with both the VHI and the DSI. In a linear regression analysis, the combination of hypertonicity of the sternocleidomastoid, the geniohyoid muscles and posterior weight bearing is the most important predictor for a high voice handicap. The combination of hypertonicity of the geniohyoid muscle, posterior weight bearing, high position of the hyoid bone, hypertonicity of the cricothyroid muscle and anteroposition of the head is the most important predictor for a low DSI score. The results of this study show the higher the score of the index, the higher the score of the voice handicap and the worse the voice quality is. Moreover, the results are indicative for the importance of assessment of muscular tension and body posture in the diagnosis of voice disorders.

  13. The Role of Occupational Voice Demand and Patient-Rated Impairment in Predicting Voice Therapy Adherence.

    Science.gov (United States)

    Ebersole, Barbara; Soni, Resha S; Moran, Kathleen; Lango, Miriam; Devarajan, Karthik; Jamal, Nausheen

    2018-05-01

    Examine the relationship among the severity of patient-perceived voice impairment, perceptual dysphonia severity, occupational voice demand, and voice therapy adherence. Identify clinical predictors of increased risk for therapy nonadherence. A retrospective cohort study of patients presenting with a chief complaint of persistent dysphonia at an interdisciplinary voice center was done. The Voice Handicap Index-10 (VHI-10) and the Voice-Related Quality of Life (V-RQOL) survey scores, clinician rating of dysphonia severity using the Grade score from the Grade, Roughness Breathiness, Asthenia, and Strain scale, occupational voice demand, and patient demographics were tested for associations with therapy adherence, defined as completion of the treatment plan. Classification and Regression Tree (CART) analysis was performed to establish thresholds for nonadherence risk. Of 166 patients evaluated, 111 were recommended for voice therapy. The therapy nonadherence rate was 56%. Occupational voice demand category, VHI-10, and V-RQOL scores were the only factors significantly correlated with therapy adherence (P demand are significantly more likely to be nonadherent with therapy than those with high occupational voice demand (P 40 is a significant cutoff point for predicting therapy nonadherence (P demand and patient perception of impairment are significantly and independently correlated with therapy adherence. A VHI-10 score of ≤9 or a V-RQOL score of >40 is a significant cutoff point for predicting nonadherence risk. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  14. Integrating cues of social interest and voice pitch in men's preferences for women's voices.

    Science.gov (United States)

    Jones, Benedict C; Feinberg, David R; Debruine, Lisa M; Little, Anthony C; Vukovic, Jovana

    2008-04-23

    Most previous studies of vocal attractiveness have focused on preferences for physical characteristics of voices such as pitch. Here we examine the content of vocalizations in interaction with such physical traits, finding that vocal cues of social interest modulate the strength of men's preferences for raised pitch in women's voices. Men showed stronger preferences for raised pitch when judging the voices of women who appeared interested in the listener than when judging the voices of women who appeared relatively disinterested in the listener. These findings show that voice preferences are not determined solely by physical properties of voices and that men integrate information about voice pitch and the degree of social interest expressed by women when forming voice preferences. Women's preferences for raised pitch in women's voices were not modulated by cues of social interest, suggesting that the integration of cues of social interest and voice pitch when men judge the attractiveness of women's voices may reflect adaptations that promote efficient allocation of men's mating effort.

  15. Perception of Paralinguistic Traits in Synthesized Voices

    DEFF Research Database (Denmark)

    Baird, Alice Emily; Hasse Jørgensen, Stina; Parada-Cabaleiro, Emilia

    2017-01-01

    Along with the rise of artificial intelligence and the internet-of-things, synthesized voices are now common in daily–life, providing us with guidance, assistance, and even companionship. From formant to concatenative synthesis, the synthesized voice continues to be defined by the same traits we...

  16. Student Voices in School-Based Assessment

    Science.gov (United States)

    Tong, Siu Yin Annie; Adamson, Bob

    2015-01-01

    The value of student voices in dialogues about learning improvement is acknowledged in the literature. This paper examines how the views of students regarding School-based Assessment (SBA), a significant shift in examination policy and practice in secondary schools in Hong Kong, have largely been ignored. The study captures student voices through…

  17. The Voice of the Technical Writer.

    Science.gov (United States)

    Euler, James S.

    The author's voice is implicit in all writing, even technical writing. It is the expression of the writer's attitude toward audience, subject matter, and self. Effective use of voice is made possible by recognizing the three roles of the technical writer: transmitter, translator, and author. As a transmitter, the writer must consciously apply an…

  18. Student Voice and the Common Core

    Science.gov (United States)

    Yonezawa, Susan

    2015-01-01

    Common Core proponents and detractors debate its merits, but students have voiced their opinion for years. Using a decade's worth of data gathered through design-research on youth voice, this article discusses what high school students have long described as more ideal learning environments for themselves--and how remarkably similar the Common…

  19. Employee voice and engagement : Connections and consequences

    NARCIS (Netherlands)

    Rees, C.; Alfes, K.; Gatenby, M.

    2013-01-01

    This paper considers the relationship between employee voice and employee engagement. Employee perceptions of voice behaviour aimed at improving the functioning of the work group are found to have both a direct impact and an indirect impact on levels of employee engagement. Analysis of data from two

  20. Speaking with the voice of authority

    CERN Multimedia

    2002-01-01

    GPB Consulting has developed a scientific approach to voice coaching. A digital recording of the voice is sent to a lab in Switzerland and analyzed by a computer programme designed by a doctor of psychology and linguistics and a scientist at CERN (1 page).

  1. Managing dysphonia in occupational voice users.

    Science.gov (United States)

    Behlau, Mara; Zambon, Fabiana; Madazio, Glaucya

    2014-06-01

    Recent advances with regard to occupational voice disorders are highlighted with emphasis on issues warranting consideration when assessing, training, and treating professional voice users. Findings include the many particularities between the various categories of professional voice users, the concept that the environment plays a major role in occupational voice disorders, and that biopsychosocial influences should be analyzed on an individual basis. Assessment via self-evaluation protocols to quantify the impact of these disorders is mandatory as a component of an evaluation and to document treatment outcomes. Discomfort or odynophonia has evolved as a critical symptom in this population. Clinical trials are limited and the complexity of the environment may be a limitation in experiment design. This review reinforced the need for large population studies of professional voice users; new data highlighted important factors specific to each group of voice users. Interventions directed at student teachers are necessities to not only improving the quality of future professionals, but also to avoid the frustration and limitations associated with chronic voice problems. The causative relationship between the work environment and voice disorders has not yet been established. Randomized controlled trials are lacking and must be a focus to enhance treatment paradigms for this population.

  2. Does CPAP treatment affect the voice?

    Science.gov (United States)

    Saylam, Güleser; Şahin, Mustafa; Demiral, Dilek; Bayır, Ömer; Yüceege, Melike Bağnu; Çadallı Tatar, Emel; Korkmaz, Mehmet Hakan

    2016-12-20

    The aim of this study was to investigate alterations in voice parameters among patients using continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea syndrome. Patients with an indication for CPAP treatment without any voice problems and with normal laryngeal findings were included and voice parameters were evaluated before and 1 and 6 months after CPAP. Videolaryngostroboscopic findings, a self-rated scale (Voice Handicap Index-10, VHI-10), perceptual voice quality assessment (GRBAS: grade, roughness, breathiness, asthenia, strain), and acoustic parameters were compared. Data from 70 subjects (48 men and 22 women) with a mean age of 44.2 ± 6.0 years were evaluated. When compared with the pre-CPAP treatment period, there was a significant increase in the VHI-10 score after 1 month of treatment and in VHI- 10 and total GRBAS scores, jitter percent (P = 0.01), shimmer percent, noise-to-harmonic ratio, and voice turbulence index after 6 months of treatment. Vague negative effects on voice parameters after the first month of CPAP treatment became more evident after 6 months. We demonstrated nonsevere alterations in the voice quality of patients under CPAP treatment. Given that CPAP is a long-term treatment it is important to keep these alterations in mind.

  3. Occupational risk factors and voice disorders.

    Science.gov (United States)

    Vilkman, E

    1996-01-01

    From the point of view of occupational health, the field of voice disorders is very poorly developed as compared, for instance, to the prevention and diagnostics of occupational hearing disorders. In fact, voice disorders have not even been recognized in the field of occupational medicine. Hence, it is obviously very rare in most countries that the voice disorder of a professional voice user, e.g. a teacher, a singer or an actor, is accepted as an occupational disease by insurance companies. However, occupational voice problems do not lack significance from the point of view of the patient. We also know from questionnaires and clinical studies that voice complaints are very common. Another example of job-related health problems, which has proved more successful in terms of its occupational health status, is the repetition strain injury of the elbow, i.e. the "tennis elbow". Its textbook definition could be used as such to describe an occupational voice disorder ("dysphonia professional is"). In the present paper the effects of such risk factors as vocal loading itself, background noise and room acoustics and low relative humidity of the air are discussed. Due to individual factors underlying the development of professional voice disorders, recommendations rather than regulations are called for. There are many simple and even relatively low-cost methods available for the prevention of vocal problems as well as for supporting rehabilitation.

  4. Why Is My Voice Changing? (For Teens)

    Science.gov (United States)

    ... enter puberty earlier or later than others. How Deep Will My Voice Get? How deep a guy's voice gets depends on his genes: ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on TeensHealth® is for ...

  5. Stage Voice Training in the London Schools.

    Science.gov (United States)

    Rubin, Lucille S.

    This report is the result of a six-week study in which the voice training offerings at four schools of drama in London were examined using interviews of teachers and directors, observation of voice classes, and attendance at studio presentations and public performances. The report covers such topics as: textbooks and references being used; courses…

  6. Predictors of Choral Directors' Voice Handicap

    Science.gov (United States)

    Schwartz, Sandra

    2013-01-01

    Vocal demands of teaching are considerable and these challenges are greater for choral directors who depend on the voice as a musical and instructive instrument. The purpose of this study was to (1) examine choral directors' vocal condition using a modified Voice Handicap Index (VHI), and (2) determine the extent to which the major variables…

  7. Channel CAT: A Tactical Link Analysis Tool

    Science.gov (United States)

    1997-09-01

    NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS CHANNEL CAT : A TACTICAL LINK ANALYSIS TOOL by Michael Glenn Coleman September 1997 Thesis...REPORT TYPE AND DATES COVERED September 1997 Master’s Thesis 4. TITLE AND SUBTITLE CHANNEL CAT : A TACTICAL LINK ANALYSIS TOOL 5. FUNDING NUMBERS 6...tool, the Channel Capacity Analysis Tool (Channel CAT ), designed to provide an automated tool for the anlysis of design decisions in developing client

  8. Voice disorders in teachers. A review.

    Science.gov (United States)

    Martins, Regina Helena Garcia; Pereira, Eny Regina Bóia Neves; Hidalgo, Caio Bosque; Tavares, Elaine Lara Mendes

    2014-11-01

    Voice disorders are very prevalent among teachers and consequences are serious. Although the literature is extensive, there are differences in the concepts and methodology related to voice problems; most studies are restricted to analyzing the responses of teachers to questionnaires and only a few studies include vocal assessments and videolaryngoscopic examinations to obtain a definitive diagnosis. To review demographic studies related to vocal disorders in teachers to analyze the diverse methodologies, the prevalence rates pointed out by the authors, the main risk factors, the most prevalent laryngeal lesions, and the repercussions of dysphonias on professional activities. The available literature (from 1997 to 2013) was narratively reviewed based on Medline, PubMed, Lilacs, SciELO, and Cochrane library databases. Excluded were articles that specifically analyzed treatment modalities and those that did not make their abstracts available in those databases. The keywords included were teacher, dysphonia, voice disorders, professional voice. Copyright © 2014 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  9. Voice pedagogy-what do we need?

    Science.gov (United States)

    Gill, Brian P; Herbst, Christian T

    2016-12-01

    The final keynote panel of the 10th Pan-European Voice Conference (PEVOC) was concerned with the topic 'Voice pedagogy-what do we need?' In this communication the panel discussion is summarized, and the authors provide a deepening discussion on one of the key questions, addressing the roles and tasks of people working with voice students. In particular, a distinction is made between (1) voice building (derived from the German term 'Stimmbildung'), primarily comprising the functional and physiological aspects of singing; (2) coaching, mostly concerned with performance skills; and (3) singing voice rehabilitation. Both public and private educators are encouraged to apply this distinction to their curricula, in order to arrive at more efficient singing teaching and to reduce the risk of vocal injury to the singers concerned.

  10. Voice Quality Estimation in Wireless Networks

    Directory of Open Access Journals (Sweden)

    Petr Zach

    2015-01-01

    Full Text Available This article deals with the impact of Wireless (Wi-Fi networks on the perceived quality of voice services. The Quality of Service (QoS metrics must be monitored in the computer network during the voice data transmission to ensure proper voice service quality the end-user has paid for, especially in the wireless networks. In addition to the QoS, research area called Quality of Experience (QoE provides metrics and methods for quality evaluation from the end-user’s perspective. This article focuses on a QoE estimation of Voice over IP (VoIP calls in the wireless networks using network simulator. Results contribute to voice quality estimation based on characteristics of the wireless network and location of a wireless client.

  11. Ion channeling

    International Nuclear Information System (INIS)

    Erramli, H.; Blondiaux, G.

    1994-01-01

    Channeling phenomenon was predicted, many years ago, by stark. The first channeling experiments were performed in 1963 by Davies and his coworkers. Parallely Robinson and Oen have investigated this process by simulating trajectories of ions in monocrystals. This technique has been combined with many methods like Rutherford Backscattering Spectrometry (R.B.S.), Particles Induced X-rays Emission (P.I.X.E) and online Nuclear Reaction (N.R.A.) to localize trace elements in the crystal or to determine crystalline quality. To use channeling for material characterization we need data about the stopping power of the incident particle in the channeled direction. The ratios of channeled to random stopping powers of silicon for irradiation in the direction have been investigated and compared to the available theoretical results. We describe few applications of ion channeling in the field of materials characterization. Special attention is given to ion channeling combined with Charged Particle Activation Analysis (C.P.A.A.) for studying the behaviour of oxygen atoms in Czochralski silicon lattices under the influence of internal gettering and in different gaseous atmospheres. Association between ion channeling and C.P.A.A was also utilised for studying the influence of the growing conditions on concentration and position of carbon atoms at trace levels in the MOVPE Ga sub (1-x) Al sub x lattice. 6 figs., 1 tab., 32 refs. (author)

  12. Identifying hidden voice and video streams

    Science.gov (United States)

    Fan, Jieyan; Wu, Dapeng; Nucci, Antonio; Keralapura, Ram; Gao, Lixin

    2009-04-01

    Given the rising popularity of voice and video services over the Internet, accurately identifying voice and video traffic that traverse their networks has become a critical task for Internet service providers (ISPs). As the number of proprietary applications that deliver voice and video services to end users increases over time, the search for the one methodology that can accurately detect such services while being application independent still remains open. This problem becomes even more complicated when voice and video service providers like Skype, Microsoft, and Google bundle their voice and video services with other services like file transfer and chat. For example, a bundled Skype session can contain both voice stream and file transfer stream in the same layer-3/layer-4 flow. In this context, traditional techniques to identify voice and video streams do not work. In this paper, we propose a novel self-learning classifier, called VVS-I , that detects the presence of voice and video streams in flows with minimum manual intervention. Our classifier works in two phases: training phase and detection phase. In the training phase, VVS-I first extracts the relevant features, and subsequently constructs a fingerprint of a flow using the power spectral density (PSD) analysis. In the detection phase, it compares the fingerprint of a flow to the existing fingerprints learned during the training phase, and subsequently classifies the flow. Our classifier is not only capable of detecting voice and video streams that are hidden in different flows, but is also capable of detecting different applications (like Skype, MSN, etc.) that generate these voice/video streams. We show that our classifier can achieve close to 100% detection rate while keeping the false positive rate to less that 1%.

  13. An empirical assessment of implementation, adaptation, and tailoring: the evaluation of CDC's National Diffusion of VOICES/VOCES.

    Science.gov (United States)

    Harshbarger, Camilla; Simmons, Gretchen; Coelho, Helen; Sloop, Kira; Collins, Charles

    2006-08-01

    The Centers for Disease Control and Prevention (CDC), through its Diffusion of Effective Behavioral Interventions (DEBI) program, trained over 260 agencies on VOICES/VOCES between August 2003 and April 2005. ORC Macro conducted interviews with agency staff 3 months after receiving VOICES/VOCES training. This article discusses the diffusion of VOICES/VOCES; agencies' adoption, adaptation, and implementation of this intervention; and needs for ongoing proactive technical assistance (TA) for agencies to successfully integrate behavioral interventions into their programs. The vastmajority of agencies implemented VOICES/VOCES with fidelity to the core elements, and agencies successfully adapted the intervention to make it more appealing to target populations. TA is needed for interventions to be successfully adapted and implemented with fidelity to the core elements, and to ensure program sustainability. More effective interventions of short duration and minimum complexity to easily match with existing resources and conditions of agency capacity among HIV prevention providers in the community are needed.

  14. Outage capacity of multicarrier systems

    KAUST Repository

    Yilmaz, Ferkan; Alouini, Mohamed-Slim

    2010-01-01

    The probability density function and the cumulative distribution function of the product of shifted Gamma variates are obtained in terms of the generalized Fox's H function. Using these new results, the exact outage capacity of multi carrier transmission through a slow Nakagami-m fading channel is presented. Moreover, it is shown that analytical and simulation results are in perfect agreement. © 2009 IEEE.

  15. Carrying Capacity

    DEFF Research Database (Denmark)

    Schroll, Henning; Andersen, Jan; Kjærgård, Bente

    2012-01-01

    A spatial planning act was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive....../cities. Four different sectors (water, food production, waste, and forests) were selected as core areas for decentralised spatial planning. Indicators for SCC and ACC were identified and assessed with regard to relevance and quantifiability. For each of the indicators selected, a legal threshold or guiding...... was introduced inIndonesia 1992 and renewed in 2008. It emphasised the planning role of decentralised authorities. The spatial planning act covers both spatial and environmental issues. It defines the concept of carrying capacity and includes definitions of supportive carrying capacity (SCC) and assimilative...

  16. On the optimum joint decoding capacity of wyner circular GCMAC by exploiting hadamard inequality

    KAUST Repository

    Shakir, Muhammad; Durrani, Tariq Salim; Alouini, Mohamed-Slim

    2010-01-01

    inequality established by exploiting the Hadamard operation between the channel fading (G) and channel slow gain (Ω) matrices. This paper demonstrates that the theoretical upper bound converges to the actual capacity for negligible channel slow gain among

  17. Covert Channels in SIP for VoIP Signalling

    Science.gov (United States)

    Mazurczyk, Wojciech; Szczypiorski, Krzysztof

    In this paper, we evaluate available steganographic techniques for SIP (Session Initiation Protocol) that can be used for creating covert channels during signaling phase of VoIP (Voice over IP) call. Apart from characterizing existing steganographic methods we provide new insights by introducing new techniques. We also estimate amount of data that can be transferred in signalling messages for typical IP telephony call.

  18. Your Cheatin' Voice Will Tell on You: Detection of Past Infidelity from Voice.

    Science.gov (United States)

    Hughes, Susan M; Harrison, Marissa A

    2017-01-01

    Evidence suggests that many physical, behavioral, and trait qualities can be detected solely from the sound of a person's voice, irrespective of the semantic information conveyed through speech. This study examined whether raters could accurately assess the likelihood that a person has cheated on committed, romantic partners simply by hearing the speaker's voice. Independent raters heard voice samples of individuals who self-reported that they either cheated or had never cheated on their romantic partners. To control for aspects that may clue a listener to the speaker's mate value, we used voice samples that did not differ between these groups for voice attractiveness, age, voice pitch, and other acoustic measures. We found that participants indeed rated the voices of those who had a history of cheating as more likely to cheat. Male speakers were given higher ratings for cheating, while female raters were more likely to ascribe the likelihood to cheat to speakers. Additionally, we manipulated the pitch of the voice samples, and for both sexes, the lower pitched versions were consistently rated to be from those who were more likely to have cheated. Regardless of the pitch manipulation, speakers were able to assess actual history of infidelity; the one exception was that men's accuracy decreased when judging women whose voices were lowered. These findings expand upon the idea that the human voice may be of value as a cheater detection tool and very thin slices of vocal information are all that is needed to make certain assessments about others.

  19. VoiceThread as a Peer Review and Dissemination Tool for Undergraduate Research

    Science.gov (United States)

    Guertin, L. A.

    2012-12-01

    VoiceThread has been utilized in an undergraduate research methods course for peer review and final research project dissemination. VoiceThread (http://www.voicethread.com) can be considered a social media tool, as it is a web-based technology with the capacity to enable interactive dialogue. VoiceThread is an application that allows a user to place a media collection online containing images, audio, videos, documents, and/or presentations in an interface that facilitates asynchronous communication. Participants in a VoiceThread can be passive viewers of the online content or engaged commenters via text, audio, video, with slide annotations via a doodle tool. The VoiceThread, which runs across browsers and operating systems, can be public or private for viewing and commenting and can be embedded into any website. Although few university students are aware of the VoiceThread platform (only 10% of the students surveyed by Ng (2012)), the 2009 K-12 edition of The Horizon Report (Johnson et al., 2009) lists VoiceThread as a tool to watch because of the opportunities it provides as a collaborative learning environment. In Fall 2011, eleven students enrolled in an undergraduate research methods course at Penn State Brandywine each conducted their own small-scale research project. Upon conclusion of the projects, students were required to create a poster summarizing their work for peer review. To facilitate the peer review process outside of class, each student-created PowerPoint file was placed in a VoiceThread with private access to only the class members and instructor. Each student was assigned to peer review five different student posters (i.e., VoiceThread images) with the audio and doodle tools to comment on formatting, clarity of content, etc. After the peer reviews were complete, the students were allowed to edit their PowerPoint poster files for a new VoiceThread. In the new VoiceThread, students were required to video record themselves describing their research

  20. A pneumatic Bionic Voice prosthesis-Pre-clinical trials of controlling the voice onset and offset.

    Directory of Open Access Journals (Sweden)

    Farzaneh Ahmadi

    Full Text Available Despite emergent progress in many fields of bionics, a functional Bionic Voice prosthesis for laryngectomy patients (larynx amputees has not yet been achieved, leading to a lifetime of vocal disability for these patients. This study introduces a novel framework of Pneumatic Bionic Voice Prostheses as an electronic adaptation of the Pneumatic Artificial Larynx (PAL device. The PAL is a non-invasive mechanical voice source, driven exclusively by respiration with an exceptionally high voice quality, comparable to the existing gold standard of Tracheoesophageal (TE voice prosthesis. Following PAL design closely as the reference, Pneumatic Bionic Voice Prostheses seem to have a strong potential to substitute the existing gold standard by generating a similar voice quality while remaining non-invasive and non-surgical. This paper designs the first Pneumatic Bionic Voice prosthesis and evaluates its onset and offset control against the PAL device through pre-clinical trials on one laryngectomy patient. The evaluation on a database of more than five hours of continuous/isolated speech recordings shows a close match between the onset/offset control of the Pneumatic Bionic Voice and the PAL with an accuracy of 98.45 ±0.54%. When implemented in real-time, the Pneumatic Bionic Voice prosthesis controller has an average onset/offset delay of 10 milliseconds compared to the PAL. Hence it addresses a major disadvantage of previous electronic voice prostheses, including myoelectric Bionic Voice, in meeting the short time-frames of controlling the onset/offset of the voice in continuous speech.

  1. A pneumatic Bionic Voice prosthesis-Pre-clinical trials of controlling the voice onset and offset.

    Science.gov (United States)

    Ahmadi, Farzaneh; Noorian, Farzad; Novakovic, Daniel; van Schaik, André

    2018-01-01

    Despite emergent progress in many fields of bionics, a functional Bionic Voice prosthesis for laryngectomy patients (larynx amputees) has not yet been achieved, leading to a lifetime of vocal disability for these patients. This study introduces a novel framework of Pneumatic Bionic Voice Prostheses as an electronic adaptation of the Pneumatic Artificial Larynx (PAL) device. The PAL is a non-invasive mechanical voice source, driven exclusively by respiration with an exceptionally high voice quality, comparable to the existing gold standard of Tracheoesophageal (TE) voice prosthesis. Following PAL design closely as the reference, Pneumatic Bionic Voice Prostheses seem to have a strong potential to substitute the existing gold standard by generating a similar voice quality while remaining non-invasive and non-surgical. This paper designs the first Pneumatic Bionic Voice prosthesis and evaluates its onset and offset control against the PAL device through pre-clinical trials on one laryngectomy patient. The evaluation on a database of more than five hours of continuous/isolated speech recordings shows a close match between the onset/offset control of the Pneumatic Bionic Voice and the PAL with an accuracy of 98.45 ±0.54%. When implemented in real-time, the Pneumatic Bionic Voice prosthesis controller has an average onset/offset delay of 10 milliseconds compared to the PAL. Hence it addresses a major disadvantage of previous electronic voice prostheses, including myoelectric Bionic Voice, in meeting the short time-frames of controlling the onset/offset of the voice in continuous speech.

  2. A pneumatic Bionic Voice prosthesis—Pre-clinical trials of controlling the voice onset and offset

    Science.gov (United States)

    Noorian, Farzad; Novakovic, Daniel; van Schaik, André

    2018-01-01

    Despite emergent progress in many fields of bionics, a functional Bionic Voice prosthesis for laryngectomy patients (larynx amputees) has not yet been achieved, leading to a lifetime of vocal disability for these patients. This study introduces a novel framework of Pneumatic Bionic Voice Prostheses as an electronic adaptation of the Pneumatic Artificial Larynx (PAL) device. The PAL is a non-invasive mechanical voice source, driven exclusively by respiration with an exceptionally high voice quality, comparable to the existing gold standard of Tracheoesophageal (TE) voice prosthesis. Following PAL design closely as the reference, Pneumatic Bionic Voice Prostheses seem to have a strong potential to substitute the existing gold standard by generating a similar voice quality while remaining non-invasive and non-surgical. This paper designs the first Pneumatic Bionic Voice prosthesis and evaluates its onset and offset control against the PAL device through pre-clinical trials on one laryngectomy patient. The evaluation on a database of more than five hours of continuous/isolated speech recordings shows a close match between the onset/offset control of the Pneumatic Bionic Voice and the PAL with an accuracy of 98.45 ±0.54%. When implemented in real-time, the Pneumatic Bionic Voice prosthesis controller has an average onset/offset delay of 10 milliseconds compared to the PAL. Hence it addresses a major disadvantage of previous electronic voice prostheses, including myoelectric Bionic Voice, in meeting the short time-frames of controlling the onset/offset of the voice in continuous speech. PMID:29466455

  3. Syllogisms delivered in an angry voice lead to improved performance and engagement of a different neural system compared to neutral voice

    Directory of Open Access Journals (Sweden)

    Kathleen Walton Smith

    2015-05-01

    Full Text Available Despite the fact that most real-world reasoning occurs in some emotional context, very little is known about the underlying behavioral and neural implications of such context. To further understand the role of emotional context in logical reasoning we scanned 15 participants with fMRI while they engaged in logical reasoning about neutral syllogisms presented through the auditory channel in a sad, angry, or neutral tone of voice. Exposure to angry voice led to improved reasoning performance compared to exposure to sad and neutral voice. A likely explanation for this effect is that exposure to expressions of anger increases selective attention toward the relevant features of target stimuli, in this case the reasoning task. Supporting this interpretation, reasoning in the context of angry voice was accompanied by activation in the superior frontal gyrus—a region known to be associated with selective attention. Our findings contribute to a greater understanding of the neural processes that underlie reasoning in an emotional context by demonstrating that two emotional contexts, despite being of the same (negative valence, have different effects on reasoning.

  4. Mindfulness of voices, self-compassion, and secure attachment in relation to the experience of hearing voices.

    Science.gov (United States)

    Dudley, James; Eames, Catrin; Mulligan, John; Fisher, Naomi

    2018-03-01

    Developing compassion towards oneself has been linked to improvement in many areas of psychological well-being, including psychosis. Furthermore, developing a non-judgemental, accepting way of relating to voices is associated with lower levels of distress for people who hear voices. These factors have also been associated with secure attachment. This study explores associations between the constructs of mindfulness of voices, self-compassion, and distress from hearing voices and how secure attachment style related to each of these variables. Cross-sectional online. One hundred and twenty-eight people (73% female; M age  = 37.5; 87.5% Caucasian) who currently hear voices completed the Self-Compassion Scale, Southampton Mindfulness of Voices Questionnaire, Relationships Questionnaire, and Hamilton Programme for Schizophrenia Voices Questionnaire. Results showed that mindfulness of voices mediated the relationship between self-compassion and severity of voices, and self-compassion mediated the relationship between mindfulness of voices and severity of voices. Self-compassion and mindfulness of voices were significantly positively correlated with each other and negatively correlated with distress and severity of voices. Mindful relation to voices and self-compassion are associated with reduced distress and severity of voices, which supports the proposed potential benefits of mindful relating to voices and self-compassion as therapeutic skills for people experiencing distress by voice hearing. Greater self-compassion and mindfulness of voices were significantly associated with less distress from voices. These findings support theory underlining compassionate mind training. Mindfulness of voices mediated the relationship between self-compassion and distress from voices, indicating a synergistic relationship between the constructs. Although the current findings do not give a direction of causation, consideration is given to the potential impact of mindful and

  5. Channel box

    International Nuclear Information System (INIS)

    Tanabe, Akira.

    1993-01-01

    In a channel box of a BWR type reactor, protruding pads are disposed in axial position on the lateral side of a channel box opposing to a control rod and facing the outer side portion of the control rod in a reactor core loaded state. In the initial loading stage of fuel assemblies, channel fasteners and spacer pads are abutted against each other in the upper portion between the channel boxes sandwiching the control rod therebetween. Further, in the lower portion, a gap as a channel for the movement of the control rod is ensured by the support of fuel support metals. If the channel box is bent toward the control rod along with reactor operation, the pads are abutted against each other to always ensure the gap through which the control rod can move easily. Further, when the pads are brought into contact with each other, the bending deformation of the channel box is corrected by urging to each other. Thus, the control rod can always be moved smoothly to attain reactor safety operation. (N.H.)

  6. Psychological effects of dysphonia in voice professionals.

    Science.gov (United States)

    Salturk, Ziya; Kumral, Tolgar Lutfi; Aydoğdu, Imran; Arslanoğlu, Ahmet; Berkiten, Güler; Yildirim, Güven; Uyar, Yavuz

    2015-08-01

    To evaluate the psychological effects of dysphonia in voice professionals compared to non-voice professionals and in both genders. Cross-sectional analysis. Forty-eight 48 voice professionals and 52 non-voice professionals with dysphonia were included in this study. All participants underwent a complete ear, nose, and throat examination and an evaluation for pathologies that might affect vocal quality. Participants were asked to complete the Turkish versions of the Voice Handicap Index-30 (VHI-30), Perceived Stress Scale (PSS), and the Hospital Anxiety and Depression Scale (HADS). HADS scores were evaluated as HADS-A (anxiety) and HADS-D (depression). Dysphonia status was evaluated by grade, roughness, breathiness, asthenia, and strain (GRBAS) scale perceptually. The results were compared statistically. Significant differences between the two groups were evident when the VHI-30 and PSS data were compared (P = .00001 and P = .00001, respectively). However, neither HADS score (HADS-A and HADS-D) differed between groups. An analysis of the scores in terms of sex revealed that females had significantly higher PSS scores (P = .006). The GRBAS scale revealed no difference between groups (P = .819, .931, .803, .655, and .803, respectively). No between-sex differences in the VHI-30 or HADS scores were evident We found that voice professionals and females experienced more stress and were more dissatisfied with their voices. 4. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  7. Reliability in perceptual analysis of voice quality.

    Science.gov (United States)

    Bele, Irene Velsvik

    2005-12-01

    This study focuses on speaking voice quality in male teachers (n = 35) and male actors (n = 36), who represent untrained and trained voice users, because we wanted to investigate normal and supranormal voices. In this study, both substantial and methodologic aspects were considered. It includes a method for perceptual voice evaluation, and a basic issue was rater reliability. A listening group of 10 listeners, 7 experienced speech-language therapists, and 3 speech-language therapist students evaluated the voices by 15 vocal characteristics using VA scales. Two sets of voice signals were investigated: text reading (2 loudness levels) and sustained vowel (3 levels). The results indicated a high interrater reliability for most perceptual characteristics. Connected speech was evaluated more reliably, especially at the normal level, but both types of voice signals were evaluated reliably, although the reliability for connected speech was somewhat higher than for vowels. Experienced listeners tended to be more consistent in their ratings than did the student raters. Some vocal characteristics achieved acceptable reliability even with a smaller panel of listeners. The perceptual characteristics grouped in 4 factors reflected perceptual dimensions.

  8. Muted 'voice': The writing of two groups of postgraduate ...

    African Journals Online (AJOL)

    The purpose of this article is to demonstrate and account for the weak emergence of 'voice' in the writing of students embarking upon their postgraduate studies in Geosciences. The two elements of 'voice' that are emphasised are 'voice' as style of expression and 'voice' as the ability to write distinctly, yet building upon ...

  9. Performance of Phonatory Deviation Diagrams in Synthesized Voice Analysis.

    Science.gov (United States)

    Lopes, Leonardo Wanderley; da Silva, Karoline Evangelista; da Silva Evangelista, Deyverson; Almeida, Anna Alice; Silva, Priscila Oliveira Costa; Lucero, Jorge; Behlau, Mara

    2018-05-02

    To analyze the performance of a phonatory deviation diagram (PDD) in discriminating the presence and severity of voice deviation and the predominant voice quality of synthesized voices. A speech-language pathologist performed the auditory-perceptual analysis of the synthesized voice (n = 871). The PDD distribution of voice signals was analyzed according to area, quadrant, shape, and density. Differences in signal distribution regarding the PDD area and quadrant were detected when differentiating the signals with and without voice deviation and with different predominant voice quality. Differences in signal distribution were found in all PDD parameters as a function of the severity of voice disorder. The PDD area and quadrant can differentiate normal voices from deviant synthesized voices. There are differences in signal distribution in PDD area and quadrant as a function of the severity of voice disorder and the predominant voice quality. However, the PDD area and quadrant do not differentiate the signals as a function of severity of voice disorder and differentiated only the breathy and rough voices from the normal and strained voices. PDD density is able to differentiate only signals with moderate and severe deviation. PDD shape shows differences between signals with different severities of voice deviation. © 2018 S. Karger AG, Basel.

  10. Quantum channels with a finite memory

    International Nuclear Information System (INIS)

    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

  11. Voicing children's critique and utopias

    DEFF Research Database (Denmark)

    Husted, Mia; Lind, Unni

    and restrictions, Call for aesthetics an sensuality, Longings for home and parents, Longings for better social relations Making children's voice visible allows preschool teachers to reflect children's knowledge and life word in pedagogical practice. Keywords: empowerment and participation, action research...... children to raise and render visible their own critique and wishes related to their everyday life in daycare. Research on how and why to engage children as participants in research and in institutional developments addresses overall interests in democratization and humanization that can be traced back...... to strategies for Nordic welfare developments and the Conventions on Children's Rights. The theoretical and methodological framework follow the lines of how to form and learn democracy of Lewin (1948) and Dewey (1916). The study is carried out as action research involving 50 children at age three to five...

  12. His Master’s Voice?

    DEFF Research Database (Denmark)

    Sörbom, Adrienne; Garsten, Christina

    This paper departs from an interest in the involvement of business leaders in the sphere of politics, in the broad sense. Many global business leaders today do much more than engage narrowly in their own corporation and its search for profit. At a general level, we are seeing a proliferation...... as political. What is the role of business in the World Economic Forum, and how do business corporations advance their interests through the WEF? The results show that corporations find a strategically positioned amplifier for their non-market interests in the WEF. The WEF functions to enhance and gain...... leverage for their ideas and priorities in a highly selective and resourceful environment. In the long run, both the market priorities and the political interests of business may be served by engagement in the WEF. However, the WEF cannot only be conceived as the extended voice of corporations. The WEF...

  13. Giving the Customer a Voice

    DEFF Research Database (Denmark)

    Van der Hoven, Christopher; Michea, Adela; Varnes, Claus

    , for example there are studies that have strongly criticized focus groups, interviews and surveys (e.g. Ulwick, 2002; Goffin et al, 2010; Sandberg, 2002). In particular, a point is made that, “…traditional market research and development approaches proved to be particularly ill-suited to breakthrough products...... the voice of the customer (VoC) through market research is well documented (Davis, 1993; Mullins and Sutherland, 1998; Cooper et al., 2002; Flint, 2002; Davilla et al., 2006; Cooper and Edgett, 2008; Cooper and Dreher, 2010; Goffin and Mitchell, 2010). However, not all research methods are well received......” (Deszca et al, 2010, p613). Therefore, in situations where traditional techniques - interviews and focus groups - are ineffective, the question is which market research techniques are appropriate, particularly for developing breakthrough products? To investigate this, an attempt was made to access...

  14. Dangertalk: Voices of abortion providers.

    Science.gov (United States)

    Martin, Lisa A; Hassinger, Jane A; Debbink, Michelle; Harris, Lisa H

    2017-07-01

    Researchers have described the difficulties of doing abortion work, including the psychosocial costs to individual providers. Some have discussed the self-censorship in which providers engage in to protect themselves and the pro-choice movement. However, few have examined the costs of this self-censorship to public discourse and social movements in the US. Using qualitative data collected during abortion providers' discussions of their work, we explore the tensions between their narratives and pro-choice discourse, and examine the types of stories that are routinely silenced - narratives we name "dangertalk". Using these data, we theorize about the ways in which giving voice to these tensions might transform current abortion discourse by disrupting false dichotomies and better reflecting the complex realities of abortion. We present a conceptual model for dangertalk in abortion discourse, connecting it to functions of dangertalk in social movements more broadly. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Mediatization: a concept, multiple voices

    Directory of Open Access Journals (Sweden)

    Pedro Gilberto GOMES

    2016-12-01

    Full Text Available Mediatization has become increasingly a key concept, fundamental, essential to describe the present and the history of media and communicative change taking place. Thus, it became part of a whole, one can not see them as a separate sphere. In this perspective, the media coverage is used as a concept to describe the process of expansion of the different technical means and consider the interrelationships between the communicative change, means and sociocultural change. However, although many researchers use the concept of mediatization, each gives you the meaning that best suits your needs. Thus, the concept of media coverage is treated with multiple voices. This paper discusses this problem and present a preliminary pre-position on the matter.

  16. Surface channeling

    International Nuclear Information System (INIS)

    Sizmann, R.; Varelas, C.

    1976-01-01

    There is experimental evidence that swift light ions incident at small angles towards single crystalline surfaces can lose an appreciable fraction of their kinetic energy during reflection. It is shown that these projectiles penetrate into the bulk surface region of the crystal. They can travel as channeled particles along long paths through the solid (surface channeling). The angular distribution and the depth history of the re-emerged projectiles are investigated by computer simulations. A considerable fraction of the penetrating projectiles re-emerges from the crystal with constant transverse energy if the angle of incidence is smaller than the critical angle for axial channeling. Analytical formulae are derived based on a diffusion model for surface channeling. A comparison with experimental data exhibits the relevance of the analytical solutions. (Auth.)

  17. Disability: a voice in Australian bioethics?

    Science.gov (United States)

    Newell, Christopher

    2003-06-01

    The rise of research and advocacy over the years to establish a disability voice in Australia with regard to bioethical issues is explored. This includes an analysis of some of the political processes and engagement in mainstream bioethical debate. An understanding of the politics of rejected knowledge is vital in understanding the muted disability voices in Australian bioethics and public policy. It is also suggested that the voices of those who are marginalised or oppressed in society, such as people with disability, have particular contribution to make in fostering critical bioethics.

  18. Unfamiliar voice identification: Effect of post-event information on accuracy and voice ratings

    Directory of Open Access Journals (Sweden)

    Harriet Mary Jessica Smith

    2014-04-01

    Full Text Available This study addressed the effect of misleading post-event information (PEI on voice ratings, identification accuracy, and confidence, as well as the link between verbal recall and accuracy. Participants listened to a dialogue between male and female targets, then read misleading information about voice pitch. Participants engaged in verbal recall, rated voices on a feature checklist, and made a lineup decision. Accuracy rates were low, especially on target-absent lineups. Confidence and accuracy were unrelated, but the number of facts recalled about the voice predicted later lineup accuracy. There was a main effect of misinformation on ratings of target voice pitch, but there was no effect on identification accuracy or confidence ratings. As voice lineup evidence from earwitnesses is used in courts, the findings have potential applied relevance.

  19. Bringing voice in policy building.

    Science.gov (United States)

    Lotrecchiano, Gaetano R; Kane, Mary; Zocchi, Mark S; Gosa, Jessica; Lazar, Danielle; Pines, Jesse M

    2017-07-03

    Purpose The purpose of this paper is to describe the use of group concept mapping (GCM) as a tool for developing a conceptual model of an episode of acute, unscheduled care from illness or injury to outcomes such as recovery, death and chronic illness. Design/methodology/approach After generating a literature review drafting an initial conceptual model, GCM software (CS Global MAX TM ) is used to organize and identify strengths and directionality between concepts generated through feedback about the model from several stakeholder groups: acute care and non-acute care providers, patients, payers and policymakers. Through online and in-person population-specific focus groups, the GCM approach seeks feedback, assigned relationships and articulated priorities from participants to produce an output map that described overarching concepts and relationships within and across subsamples. Findings A clustered concept map made up of relational data points that produced a taxonomy of feedback was used to update the model for use in soliciting additional feedback from two technical expert panels (TEPs), and finally, a public comment exercise was performed. The results were a stakeholder-informed improved model for an acute care episode, identified factors that influence process and outcomes, and policy recommendations, which were delivered to the Department of Health and Human Services's (DHHS) Assistant Secretary for Preparedness and Response. Practical implications This study provides an example of the value of cross-population multi-stakeholder input to increase voice in shared problem health stakeholder groups. Originality/value This paper provides GCM results and a visual analysis of the relational characteristics both within and across sub-populations involved in the study. It also provides an assessment of observational key factors supporting how different stakeholder voices can be integrated to inform model development and policy recommendations.

  20. Spark Channels

    Energy Technology Data Exchange (ETDEWEB)

    Haydon, S. C. [Department of Physics, University of New England, Armidale, NSW (Australia)

    1968-04-15

    A brief summary is given of the principal methods used for initiating spark channels and the various highly time-resolved techniques developed recently for studies with nanosecond resolution. The importance of the percentage overvoltage in determining the early history and subsequent development of the various phases of the growth of the spark channel is discussed. An account is then given of the recent photographic, oscillographic and spectroscopic investigations of spark channels initiated by co-axial cable discharges of spark gaps at low [{approx} 1%] overvoltages. The phenomena observed in the development of the immediate post-breakdown phase, the diffuse glow structure, the growth of the luminous filament and the final formation of the spark channel in hydrogen are described. A brief account is also given of the salient features emerging from corresponding studies of highly overvolted spark gaps in which the spark channel develops from single avalanche conditions. The essential differences between the two types of channel formation are summarized and possible explanations of the general features are indicated. (author)

  1. Exerting Capacity.

    Science.gov (United States)

    Leger, J Michael; Phillips, Carolyn A

    2017-05-01

    Patient safety has been at the forefront of nursing research since the release of the Institute of Medicine's report estimating the number of preventable adverse events in hospital settings; yet no research to date has incorporated the perspectives of bedside nurses using classical grounded theory (CGT) methodology. This CGT study explored the perceptions of bedside registered nurses regarding patient safety in adult acute care hospitals. Data analysis used three techniques unique to CGT-the constant comparative method, coding, and memoing-to explore the values, realities, and beliefs of bedside nurses about patient safety. The analysis resulted in a substantive theory, Exerting Capacity, which explained how bedside nurses balance the demands of keeping their patients safe. Exerting Capacity has implications for health care organization leaders, nursing leaders, and bedside nurses; it also has indications for future research into the concept of patient safety.

  2. Making social media work: finding a library voice

    Directory of Open Access Journals (Sweden)

    Zelda Chatten

    2017-11-01

    Full Text Available The social media team at the University of Liverpool Library runs a popular verified Twitter account with over 9,000 followers and is enthusiastically involved in a variety of social media platforms. Since starting a period of sustained improvement, our use of social media has progressed from being a passive channel used to broadcast news and service changes to being an active method of communication in a digital space our users already inhabit. Working collaboratively, the social media team has established a cohesive and clear library voice with a consistent style and tone. This article looks at the development of the library voice with a particular focus on the use of creative, interactive and fun methods to cultivate the library personality. It also covers some of the challenges associated with this type of relaxed and experimental approach to social media and gives examples of special events used to engage and interact with students. 'Based on a lightning talk and poster session presented at the 40th UKSG Annual Conference, Harrogate, April 2017 '

  3. Connections between voice ergonomic risk factors in classrooms and teachers' voice production.

    Science.gov (United States)

    Rantala, Leena M; Hakala, Suvi; Holmqvist, Sofia; Sala, Eeva

    2012-01-01

    The aim of the study was to investigate if voice ergonomic risk factors in classrooms correlated with acoustic parameters of teachers' voice production. The voice ergonomic risk factors in the fields of working culture, working postures and indoor air quality were assessed in 40 classrooms using the Voice Ergonomic Assessment in Work Environment - Handbook and Checklist. Teachers (32 females, 8 males) from the above-mentioned classrooms recorded text readings before and after a working day. Fundamental frequency, sound pressure level (SPL) and the slope of the spectrum (alpha ratio) were analyzed. The higher the number of the risk factors in the classrooms, the higher SPL the teachers used and the more strained the males' voices (increased alpha ratio) were. The SPL was already higher before the working day in the teachers with higher risk than in those with lower risk. In the working environment with many voice ergonomic risk factors, speakers increase voice loudness and use more strained voice quality (males). A practical implication of the results is that voice ergonomic assessments are needed in schools. Copyright © 2013 S. Karger AG, Basel.

  4. [Applicability of Voice Handicap Index to the evaluation of voice therapy effectiveness in teachers].

    Science.gov (United States)

    Niebudek-Bogusz, Ewa; Kuzańska, Anna; Błoch, Piotr; Domańska, Maja; Woźnicka, Ewelina; Politański, Piotr; Sliwińska-Kowalska, Mariola

    2007-01-01

    The aim of this study was to assess the applicability of Voice Handicap Index (VHI) to the evaluation of effectiveness of functional voice disorders treatment in teachers. The subjects were 45 female teachers with functional dysphonia who evaluated their voice problems according to the subjective VHI scale before and after phoniatric management. Group I (29 patients) were subjected to vocal training, whereas group II (16 patients) received only voice hygiene instructions. The results demonstrated that differences in the mean VHI score before and after phoniatric treatment were significantly higher in group 1 than in group II (p teacher's dysphonia.

  5. Influence of classroom acoustics on the voice levels of teachers with and without voice problems: a field study

    DEFF Research Database (Denmark)

    Pelegrin Garcia, David; Lyberg-Åhlander, Viveka; Rydell, Roland

    2010-01-01

    of the classroom. The results thus suggest that teachers with voice problems are more aware of classroom acoustic conditions than their healthy colleagues and make use of the more supportive rooms to lower their voice levels. This behavior may result from an adaptation process of the teachers with voice problems...... of the voice problems was made with a questionnaire and a laryngological examination. During teaching, the sound pressure level at the teacher’s position was monitored. The teacher’s voice level and the activity noise level were separated using mixed Gaussians. In addition, objective acoustic parameters...... of Reverberation Time and Voice Support were measured in the 30 empty classrooms of the study. An empirical model shows that the measured voice levels depended on the activity noise levels and the voice support. Teachers with and without voice problems were differently affected by the voice support...

  6. Maximizing the optical network capacity.

    Science.gov (United States)

    Bayvel, Polina; Maher, Robert; Xu, Tianhua; Liga, Gabriele; Shevchenko, Nikita A; Lavery, Domaniç; Alvarado, Alex; Killey, Robert I

    2016-03-06

    Most of the digital data transmitted are carried by optical fibres, forming the great part of the national and international communication infrastructure. The information-carrying capacity of these networks has increased vastly over the past decades through the introduction of wavelength division multiplexing, advanced modulation formats, digital signal processing and improved optical fibre and amplifier technology. These developments sparked the communication revolution and the growth of the Internet, and have created an illusion of infinite capacity being available. But as the volume of data continues to increase, is there a limit to the capacity of an optical fibre communication channel? The optical fibre channel is nonlinear, and the intensity-dependent Kerr nonlinearity limit has been suggested as a fundamental limit to optical fibre capacity. Current research is focused on whether this is the case, and on linear and nonlinear techniques, both optical and electronic, to understand, unlock and maximize the capacity of optical communications in the nonlinear regime. This paper describes some of them and discusses future prospects for success in the quest for capacity. © 2016 The Authors.

  7. Former Auctioneer Finds Voice After Aphasia

    Science.gov (United States)

    ... Aphasia Follow us Former Auctioneer Finds Voice After Aphasia Speech impairment changed his life One unremarkable September ... 10 Tips for Communicating with Someone who has Aphasia Talk to them in a quiet, calm, relaxed ...

  8. Voice Based City Panic Button System

    Science.gov (United States)

    Febriansyah; Zainuddin, Zahir; Bachtiar Nappu, M.

    2018-03-01

    The development of voice activated panic button application aims to design faster early notification of hazardous condition in community to the nearest police by using speech as the detector where the current application still applies touch-combination on screen and use coordination of orders from control center then the early notification still takes longer time. The method used in this research was by using voice recognition as the user voice detection and haversine formula for the comparison of closest distance between the user and the police. This research was equipped with auto sms, which sent notification to the victim’s relatives, that was also integrated with Google Maps application (GMaps) as the map to the victim’s location. The results show that voice registration on the application reaches 100%, incident detection using speech recognition while the application is running is 94.67% in average, and the auto sms to the victim relatives reaches 100%.

  9. A model to explain human voice production

    Science.gov (United States)

    Vilas Bôas, C. S. N.; Gobara, S. T.

    2018-05-01

    This article presents a device constructed with low-cost material to demonstrate and explain voice production. It also provides a contextualized, interdisciplinary approach to introduce the study of sound waves.

  10. Control of automated system with voice commands

    OpenAIRE

    Švara, Denis

    2012-01-01

    In smart houses contemporary achievements in the fields of automation, communications, security and artificial intelligence, increase comfort and improve the quality of user's lifes. For the purpose of this thesis we developed a system for managing a smart house with voice commands via smart phone. We focused at voice commands most. We want move from communication with fingers - touches, to a more natural, human relationship - speech. We developed the entire chain of communication, by which t...

  11. Voice disorders in Nigerian primary school teachers.

    Science.gov (United States)

    Akinbode, R; Lam, K B H; Ayres, J G; Sadhra, S

    2014-07-01

    The prolonged use or abuse of voice may lead to vocal fatigue and vocal fold tissue damage. School teachers routinely use their voices intensively at work and are therefore at a higher risk of dysphonia. To determine the prevalence of voice disorders among primary school teachers in Lagos, Nigeria, and to explore associated risk factors. Teaching and non-teaching staff from 19 public and private primary schools completed a self-administered questionnaire to obtain information on personal lifestyles, work experience and environment, and voice disorder symptoms. Dysphonia was defined as the presence of at least one of the following: hoarseness, repetitive throat clearing, tired voice or straining to speak. A total of 341 teaching and 155 non-teaching staff participated. The prevalence of dysphonia in teachers was 42% compared with 18% in non-teaching staff. A significantly higher proportion of the teachers reported that voice symptoms had affected their ability to communicate effectively. School type (public/private) did not predict the presence of dysphonia. Statistically significant associations were found for regular caffeinated drink intake (odds ratio [OR] = 3.07; 95% confidence interval [CI]: 1.51-6.62), frequent upper respiratory tract infection (OR = 3.60; 95% CI: 1.39-9.33) and raised voice while teaching (OR = 10.1; 95% CI: 5.07-20.2). Nigerian primary school teachers were at risk for dysphonia. Important environment and personal factors were upper respiratory infection, the need to frequently raise the voice when teaching and regular intake of caffeinated drinks. Dysphonia was not associated with age or years of teaching. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Voice, (inter-)subjectivity, and real time recurrent interaction.

    Science.gov (United States)

    Cummins, Fred

    2014-01-01

    Received approaches to a unified phenomenon called "language" are firmly committed to a Cartesian view of distinct unobservable minds. Questioning this commitment leads us to recognize that the boundaries conventionally separating the linguistic from the non-linguistic can appear arbitrary, omitting much that is regularly present during vocal communication. The thesis is put forward that uttering, or voicing, is a much older phenomenon than the formal structures studied by the linguist, and that the voice has found elaborations and codifications in other domains too, such as in systems of ritual and rite. Voice, it is suggested, necessarily gives rise to a temporally bound subjectivity, whether it is in inner speech (Descartes' "cogito"), in conversation, or in the synchronized utterances of collective speech found in prayer, protest, and sports arenas world wide. The notion of a fleeting subjective pole tied to dynamically entwined participants who exert reciprocal influence upon each other in real time provides an insightful way to understand notions of common ground, or socially shared cognition. It suggests that the remarkable capacity to construct a shared world that is so characteristic of Homo sapiens may be grounded in this ability to become dynamically entangled as seen, e.g., in the centrality of joint attention in human interaction. Empirical evidence of dynamic entanglement in joint speaking is found in behavioral and neuroimaging studies. A convergent theoretical vocabulary is now available in the concept of participatory sense-making, leading to the development of a rich scientific agenda liberated from a stifling metaphysics that obscures, rather than illuminates, the means by which we come to inhabit a shared world.

  13. Voice, (Inter-Subjectivity, and Real Time Recurrent Interaction

    Directory of Open Access Journals (Sweden)

    Fred eCummins

    2014-07-01

    Full Text Available Received approaches to a unified phenomenon called language are firmly committed to a Cartesian view of distinct unobservable minds. Questioning this commitment leads us to recognize that the boundaries conventionally separating the linguistic from the non-linguistic can appear arbitrary, omitting much that is regularly present during vocal communication. The thesis is put forward that uttering, or voicing, is a much older phenomenon than the formal structures studied by the linguist, and that the voice has found elaborations and codifications in other domains too, such as in systems of ritual and rite. Voice, it is suggested, necessarily gives rise to a temporally bound subjectivity, whether it is in inner speech (Descartes' cogito, in conversation, or in the synchronized utterances of collective speech found in prayer, protest and sports arenas world wide. The notion of a fleeting subjective pole tied to dynamically entwined participants who exert reciprocal influence upon each other in real time provides an insightful way to understand notions of common ground, or socially shared cognition. It suggests that the remarkable capacity to construct a shared world that is so characteristic of Homo sapiens may be grounded in this ability to become dynamically entangled as seen, e.g., in the centrality of joint attention in human interaction. Empirical evidence of dynamic entanglement in joint speaking is found in behavioral and neuroimaging studies. A convergent theoretical vocabulary is now available in the concept of participatory sense-making, leading to the development of a rich scientific agenda liberated from a stifling metaphysics that obscures, rather than illuminates, the means by which we come to inhabit a shared world.

  14. Voicing Others’ Voices: Spotlighting the Researcher as Narrator

    Directory of Open Access Journals (Sweden)

    Dan O’SULLIVAN

    2015-12-01

    Full Text Available As qualitative research undertakings are not independent of the researcher, the “indissoluble interrelationship between interpreter and interpretation” (Thomas & James, 2006, p. 782 renders it necessary for researchers to understand that their text is a representation, a version of the truth that is the product of writerly choices, and that it is discursive. Endlessly creative, artistic and political, as there is no single interpretative truth, the interpretative process facilitates the refashioning of representations, the remaking of choices and the probing of discourses. As a consequence of the particularity of any researcher’s account, issues pertaining to researcher identity and authorial stance always remain central to research endeavours (Kamler & Thomson, 2006, p. 68; Denzin & Lincoln 2011, pp. 14-15. Therefore, researchers are encouraged to be reflexive about their analyses and research accounts (Elliott, 2005, p. 152, as reflexivity helps spotlight the role of the researcher as narrator. In turn, spotlighting the researcher as narrator foregrounds a range of complex issues about voice, representation and interpretive authority (Chase, 2005, p. 657; Genishi & Glupczynski, 2006, p. 671; Eisenhart, 2006. In essence, therefore, this paper is reflective of the challenges of “doing” qualitative research in educational settings. Its particular focus-the shaping of beginning primary teachers’ identities, in Ireland, throughout the course of their initial year of occupational experience, post-graduation- endeavours to highlight issues pertaining to the researcher as narrator (O’Sullivan, 2014.

  15. Voicing others’ voices: Spotlighting the researcher as narrator

    Directory of Open Access Journals (Sweden)

    Dan O'Sullivan

    2015-09-01

    Full Text Available As qualitative research undertakings are not independent of the researcher, the “indissoluble interrelationship between interpreter and interpretation” (Thomas & James, 2006, p. 782 renders it necessary for researchers to understand that their text is a representation, a version of the truth that is the product of writerly choices, and that it is discursive. Endlessly creative, artistic and political, as there is no single interpretative truth, the interpretative process facilitates the refashioning of representations, the remaking of choices and the probing of discourses. As a consequence of the particularity of any researcher’s account, issues pertaining to researcher identity and authorial stance always remain central to research endeavours (Kamler & Thomson, 2006, p. 68; Denzin & Lincoln 2011, pp. 14-15. Therefore, researchers are encouraged to be reflexive about their analyses and research accounts (Elliott, 2005, p. 152, as reflexivity helps spotlight the role of the researcher as narrator. In turn, spotlighting the researcher as narrator foregrounds a range of complex issues about voice, representation and interpretive authority (Chase, 2005, p. 657; Genishi & Glupczynski, 2006, p. 671; Eisenhart, 2006. In essence, therefore, this paper is reflective of the challenges of “doing” qualitative research in educational settings. Its particular focus-the shaping of beginning primary teachers’ identities, in Ireland, throughout the course of their initial year of occupational experience, post-graduation- endeavours to highlight issues pertaining to the researcher as narrator (O’Sullivan, 2014.

  16. Voice pitch influences perceptions of sexual infidelity.

    Science.gov (United States)

    O'Connor, Jillian J M; Re, Daniel E; Feinberg, David R

    2011-02-28

    Sexual infidelity can be costly to members of both the extra-pair and the paired couple. Thus, detecting infidelity risk is potentially adaptive if it aids in avoiding cuckoldry or loss of parental and relationship investment. Among men, testosterone is inversely related to voice pitch, relationship and offspring investment, and is positively related to the pursuit of short-term relationships, including extra-pair sex. Among women, estrogen is positively related to voice pitch, attractiveness, and the likelihood of extra-pair involvement. Although prior work has demonstrated a positive relationship between men's testosterone levels and infidelity, this study is the first to investigate attributions of infidelity as a function of sexual dimorphism in male and female voices. We found that men attributed high infidelity risk to feminized women's voices, but not significantly more often than did women. Women attributed high infidelity risk to masculinized men's voices at significantly higher rates than did men. These data suggest that voice pitch is used as an indicator of sexual strategy in addition to underlying mate value. The aforementioned attributions may be adaptive if they prevent cuckoldry and/or loss of parental and relationship investment via avoidance of partners who may be more likely to be unfaithful.

  17. Voice Pitch Influences Perceptions of Sexual Infidelity

    Directory of Open Access Journals (Sweden)

    Jillian J.M. O'Connor

    2011-01-01

    Full Text Available Sexual infidelity can be costly to members of both the extra-pair and the paired couple. Thus, detecting infidelity risk is potentially adaptive if it aids in avoiding cuckoldry or loss of parental and relationship investment. Among men, testosterone is inversely related to voice pitch, relationship and offspring investment, and is positively related to the pursuit of short-term relationships, including extra-pair sex. Among women, estrogen is positively related to voice pitch, attractiveness, and the likelihood of extra-pair involvement. Although prior work has demonstrated a positive relationship between men's testosterone levels and infidelity, this study is the first to investigate attributions of infidelity as a function of sexual dimorphism in male and female voices. We found that men attributed high infidelity risk to feminized women's voices, but not significantly more often than did women. Women attributed high infidelity risk to masculinized men's voices at significantly higher rates than did men. These data suggest that voice pitch is used as an indicator of sexual strategy in addition to underlying mate value. The aforementioned attributions may be adaptive if they prevent cuckoldry and/or loss of parental and relationship investment via avoidance of partners who may be more likely to be unfaithful.

  18. Multivariate sensitivity to voice during auditory categorization.

    Science.gov (United States)

    Lee, Yune Sang; Peelle, Jonathan E; Kraemer, David; Lloyd, Samuel; Granger, Richard

    2015-09-01

    Past neuroimaging studies have documented discrete regions of human temporal cortex that are more strongly activated by conspecific voice sounds than by nonvoice sounds. However, the mechanisms underlying this voice sensitivity remain unclear. In the present functional MRI study, we took a novel approach to examining voice sensitivity, in which we applied a signal detection paradigm to the assessment of multivariate pattern classification among several living and nonliving categories of auditory stimuli. Within this framework, voice sensitivity can be interpreted as a distinct neural representation of brain activity that correctly distinguishes human vocalizations from other auditory object categories. Across a series of auditory categorization tests, we found that bilateral superior and middle temporal cortex consistently exhibited robust sensitivity to human vocal sounds. Although the strongest categorization was in distinguishing human voice from other categories, subsets of these regions were also able to distinguish reliably between nonhuman categories, suggesting a general role in auditory object categorization. Our findings complement the current evidence of cortical sensitivity to human vocal sounds by revealing that the greatest sensitivity during categorization tasks is devoted to distinguishing voice from nonvoice categories within human temporal cortex. Copyright © 2015 the American Physiological Society.

  19. Voice Quality in Mobile Telecommunication System

    Directory of Open Access Journals (Sweden)

    Evaldas Stankevičius

    2013-05-01

    Full Text Available The article deals with methods measuring the quality of voice transmitted over the mobile network as well as related problem, algorithms and options. It presents the created voice quality measurement system and discusses its adequacy as well as efficiency. Besides, the author presents the results of system application under the optimal hardware configuration. Under almost ideal conditions, the system evaluates the voice quality with MOS 3.85 average estimate; while the standardized TEMS Investigation 9.0 has 4.05 average MOS estimate. Next, the article presents the discussion of voice quality predictor implementation and investigates the predictor using nonlinear and linear prediction methods of voice quality dependence on the mobile network settings. Nonlinear prediction using artificial neural network resulted in the correlation coefficient of 0.62. While the linear prediction method using the least mean squares resulted in the correlation coefficient of 0.57. The analytical expression of voice quality features from the three network parameters: BER, C / I, RSSI is given as well.Article in Lithuanian

  20. A Perspective on the MIMO Wiretap Channel

    KAUST Repository

    Oggier, Frederique; Hassibi, Babak

    2015-01-01

    A wiretap channel is a communication channel between a transmitter Alice and a legitimate receiver Bob, in the presence of an eavesdropper Eve. The goal of communication is to achieve reliability between Alice and Bob, but also confidentiality despite Eve’s presence. Wiretap channels are declined in all kinds of flavors, depending on the underlying channels used by the three players: discrete memoryless channels, additive Gaussian noise channels, or fading channels, to name a few. In this survey, we focus on the case where the three players use multiple-antenna channels with Gaussian noise to communicate. After summarizing known results for multiple-input–multiple-output (MIMO) channels, both in terms of achievable reliable data rate (capacity) and code design, we introduce the MIMO wiretap channel. We then state the MIMO wiretap capacity, summarize the idea of the proof(s) behind this result, and comment on the insights given by the proofs on the physical meaning of the secrecy capacity. We finally discuss design criteria for MIMO wiretap codes.

  1. A Perspective on the MIMO Wiretap Channel

    KAUST Repository

    Oggier, Frederique

    2015-10-01

    A wiretap channel is a communication channel between a transmitter Alice and a legitimate receiver Bob, in the presence of an eavesdropper Eve. The goal of communication is to achieve reliability between Alice and Bob, but also confidentiality despite Eve’s presence. Wiretap channels are declined in all kinds of flavors, depending on the underlying channels used by the three players: discrete memoryless channels, additive Gaussian noise channels, or fading channels, to name a few. In this survey, we focus on the case where the three players use multiple-antenna channels with Gaussian noise to communicate. After summarizing known results for multiple-input–multiple-output (MIMO) channels, both in terms of achievable reliable data rate (capacity) and code design, we introduce the MIMO wiretap channel. We then state the MIMO wiretap capacity, summarize the idea of the proof(s) behind this result, and comment on the insights given by the proofs on the physical meaning of the secrecy capacity. We finally discuss design criteria for MIMO wiretap codes.

  2. Voice Use Among Music Theory Teachers: A Voice Dosimetry and Self-Assessment Study.

    Science.gov (United States)

    Schiller, Isabel S; Morsomme, Dominique; Remacle, Angélique

    2017-07-25

    This study aimed (1) to investigate music theory teachers' professional and extra-professional vocal loading and background noise exposure, (2) to determine the correlation between vocal loading and background noise, and (3) to determine the correlation between vocal loading and self-evaluation data. Using voice dosimetry, 13 music theory teachers were monitored for one workweek. The parameters analyzed were voice sound pressure level (SPL), fundamental frequency (F0), phonation time, vocal loading index (VLI), and noise SPL. Spearman correlation was used to correlate vocal loading parameters (voice SPL, F0, and phonation time) and noise SPL. Each day, the subjects self-assessed their voice using visual analog scales. VLI and self-evaluation data were correlated using Spearman correlation. Vocal loading parameters and noise SPL were significantly higher in the professional than in the extra-professional environment. Voice SPL, phonation time, and female subjects' F0 correlated positively with noise SPL. VLI correlated with self-assessed voice quality, vocal fatigue, and amount of singing and speaking voice produced. Teaching music theory is a profession with high vocal demands. More background noise is associated with increased vocal loading and may indirectly increase the risk for voice disorders. Correlations between VLI and self-assessments suggest that these teachers are well aware of their vocal demands and feel their effect on voice quality and vocal fatigue. Visual analog scales seem to represent a useful tool for subjective vocal loading assessment and associated symptoms in these professional voice users. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  3. Capacity Building

    International Nuclear Information System (INIS)

    Molloy, Brian; Mallick, Shahid

    2014-01-01

    Outcomes & Recommendations: • Significant increase needed in the nuclear workforce both to replace soon-to-retire current generation and to staff large numbers of new units planned • Key message, was the importance of an integrated approach to workforce development. • IAEA and other International Organisations were asked to continue to work on Knowledge Management, Networks and E&T activities • IAEA requested to conduct Global Survey of HR needs – survey initiated but only 50% of operating countries (30% of capacity) took part, so results inconclusive

  4. Information Transmission and Entanglement Distribution Over Bosonic Channels

    National Research Council Canada - National Science Library

    Shapiro, Jeffrey H; Personick, Stewart D; Guha, Saikat

    2008-01-01

    .... This program established an inner bound on the capacity region for the Bosonic broadcast channel, and showed that this inner bound is in fact the capacity region if a new minimum output entropy conjecture is true...

  5. MARKETING CHANNELS

    Directory of Open Access Journals (Sweden)

    Ljiljana Stošić Mihajlović

    2014-07-01

    Full Text Available Marketing channel is a set of entities and institutions, completion of distribution and marketing activities, attend the efficient and effective networking of producers and consumers. Marketing channels include the total flows of goods, money and information taking place between the institutions in the system of marketing, establishing a connection between them. The functions of the exchange, the physical supply and service activities, inherent in the system of marketing and trade. They represent paths which products and services are moving after the production, which will ultimately end up buying and eating by the user.

  6. Using quality function deployment to capture the voice of the customer and translate it into the voice of the provider.

    Science.gov (United States)

    Chaplin, E; Bailey, M; Crosby, R; Gorman, D; Holland, X; Hippe, C; Hoff, T; Nawrocki, D; Pichette, S; Thota, N

    1999-06-01

    Health care has a number of historical barriers to capturing the voice of the customer and to incorporating customer wants into health care services, whether the customer is a patient, an insurer, or a community. Quality function deployment (QFD) is a set of tools and practices that can help overcome these barriers to form a process for the planning and design or redesign of products and services. The goal of the project was to increase referral volume and to improve a rehabilitation hospital's capacity to provide comprehensive medical and/or legal evaluations for people with complex and catastrophic injuries or illnesses. HIGH-LEVEL VIEW OF QFD AS A PROCESS: The steps in QFD are as follows: capture of the voice of the customer, quality deployment, functions deployment, failure mode deployment, new process deployment, and task deployment. The output of each step becomes the input to a matrix tool or table of the next step of the process. In 3 1/2 months a nine-person project team at Continental Rehabilitation Hospital (San Diego) used QFD tools to capture the voice of the customer, use these data as the basis for a questionnaire on important qualities of service from the customer's perspective, obtain competitive data on how the organization was perceived to be meeting the demanded qualities, identify measurable dimensions and targets of these qualities, and incorporate the functions and tasks into the delivery of service which are necessary to meet the demanded qualities. The future of providing health care services will belong to organizations that can adapt to a rapidly changing environment and to demands for new products and services that are produced and delivered in new ways.

  7. Updating signal typing in voice: addition of type 4 signals.

    Science.gov (United States)

    Sprecher, Alicia; Olszewski, Aleksandra; Jiang, Jack J; Zhang, Yu

    2010-06-01

    The addition of a fourth type of voice to Titze's voice classification scheme is proposed. This fourth voice type is characterized by primarily stochastic noise behavior and is therefore unsuitable for both perturbation and correlation dimension analysis. Forty voice samples were classified into the proposed four types using narrowband spectrograms. Acoustic, perceptual, and correlation dimension analyses were completed for all voice samples. Perturbation measures tended to increase with voice type. Based on reliability cutoffs, the type 1 and type 2 voices were considered suitable for perturbation analysis. Measures of unreliability were higher for type 3 and 4 voices. Correlation dimension analyses increased significantly with signal type as indicated by a one-way analysis of variance. Notably, correlation dimension analysis could not quantify the type 4 voices. The proposed fourth voice type represents a subset of voices dominated by noise behavior. Current measures capable of evaluating type 4 voices provide only qualitative data (spectrograms, perceptual analysis, and an infinite correlation dimension). Type 4 voices are highly complex and the development of objective measures capable of analyzing these voices remains a topic of future investigation.

  8. Quantum communication under channel uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Noetzel, Janis Christian Gregor

    2012-09-06

    This work contains results concerning transmission of entanglement and subspaces as well as generation of entanglement in the limit of arbitrary many uses of compound- and arbitrarily varying quantum channels (CQC, AVQC). In both cases, the channel is described by a set of memoryless channels. Only forward communication between one sender and one receiver is allowed. A code is said to be ''good'' only, if it is ''good'' for every channel out of the set. Both settings describe a scenario, in which sender and receiver have only limited channel knowledge. For different amounts of information about the channel available to sender or receiver, coding theorems are proven for the CQC. For the AVQC, both deterministic and randomised coding schemes are considered. Coding theorems are proven, as well as a quantum analogue of the Ahlswede-dichotomy. The connection to zero-error capacities of stationary memoryless quantum channels is investigated. The notion of symmetrisability is defined and used for both classes of channels.

  9. Regeneration limit of classical Shannon capacity

    Science.gov (United States)

    Sorokina, M. A.; Turitsyn, S. K.

    2014-05-01

    Since Shannon derived the seminal formula for the capacity of the additive linear white Gaussian noise channel, it has commonly been interpreted as the ultimate limit of error-free information transmission rate. However, the capacity above the corresponding linear channel limit can be achieved when noise is suppressed using nonlinear elements; that is, the regenerative function not available in linear systems. Regeneration is a fundamental concept that extends from biology to optical communications. All-optical regeneration of coherent signal has attracted particular attention. Surprisingly, the quantitative impact of regeneration on the Shannon capacity has remained unstudied. Here we propose a new method of designing regenerative transmission systems with capacity that is higher than the corresponding linear channel, and illustrate it by proposing application of the Fourier transform for efficient regeneration of multilevel multidimensional signals. The regenerative Shannon limit—the upper bound of regeneration efficiency—is derived.

  10. Diagnostic value of voice acoustic analysis in assessment of occupational voice pathologies in teachers.

    Science.gov (United States)

    Niebudek-Bogusz, Ewa; Fiszer, Marta; Kotylo, Piotr; Sliwinska-Kowalska, Mariola

    2006-01-01

    It has been shown that teachers are at risk of developing occupational dysphonia, which accounts for over 25% of all occupational diseases diagnosed in Poland. The most frequently used method of diagnosing voice diseases is videostroboscopy. However, to facilitate objective evaluation of voice efficiency as well as medical certification of occupational voice disorders, it is crucial to implement quantitative methods of voice assessment, particularly voice acoustic analysis. The aim of the study was to assess the results of acoustic analysis in 66 female teachers (aged 40-64 years), including 35 subjects with occupational voice pathologies (e.g., vocal nodules) and 31 subjects with functional dysphonia. The acoustic analysis was performed using the IRIS software, before and after a 30-minute vocal loading test. All participants were subjected also to laryngological and videostroboscopic examinations. After the vocal effort, the acoustic parameters displayed statistically significant abnormalities, mostly lowered fundamental frequency (Fo) and incorrect values of shimmer and noise to harmonic ratio. To conclude, quantitative voice acoustic analysis using the IRIS software seems to be an effective complement to voice examinations, which is particularly helpful in diagnosing occupational dysphonia.

  11. Analysis of failure of voice production by a sound-producing voice prosthesis

    NARCIS (Netherlands)

    van der Torn, M.; van Gogh, C.D.L.; Verdonck-de Leeuw, I M; Festen, J.M.; Mahieu, H.F.

    OBJECTIVE: To analyse the cause of failing voice production by a sound-producing voice prosthesis (SPVP). METHODS: The functioning of a prototype SPVP is described in a female laryngectomee before and after its sound-producing mechanism was impeded by tracheal phlegm. This assessment included:

  12. Phonomicrosurgery in Vocal Fold Nodules: Quantification of Outcomes in Professional and Non-Professional Voice Users.

    Science.gov (United States)

    Caffier, Philipp P; Salmen, Tatjana; Ermakova, Tatiana; Forbes, Eleanor; Ko, Seo-Rin; Song, Wen; Gross, Manfred; Nawka, Tadeus

    2017-12-01

    There are few data demonstrating the specific extent to which surgical intervention for vocal fold nodules (VFN) improves vocal function in professional (PVU) and non-professional voice users (NVU). The objective of this study was to compare and quantify results after phonomicrosurgery for VFN in these patient groups. In a prospective clinical study, surgery was performed via microlaryngoscopy in 37 female patients with chronic VFN manifestations (38±12 yrs, mean±SD). Pre- and postoperative evaluations of treatment efficacy comprised videolaryngostroboscopy, auditory-perceptual voice assessment, voice range profile (VRP), acoustic-aerodynamic analysis, and voice handicap index (VHI-9i). The dysphonia severity index (DSI) was compared with the vocal extent measure (VEM). PVU (n=24) and NVU (n=13) showed comparable laryngeal findings and levels of suffering (VHI-9i 16±7 vs 17±8), but PVU had a better pretherapeutic vocal range (26.8±7.4 vs 17.7±5.1 semitones, p<0.001) and vocal capacity (VEM 106±18 vs 74±29, p<0.01). Three months postoperatively, all patients had straight vocal fold edges, complete glottal closure, and recovered mucosal wave propagation. The mean VHI-9i score decreased by 8±6 points. DSI increased from 4.0±2.4 to 5.5±2.4, and VEM from 95±27 to 108±23 (p<0.001). Both parameters correlated significantly (rs=0.82). The average vocal range increased by 4.1±5.3 semitones, and the mean speaking pitch lowered by 0.5±1.4 semitones. These results confirm that phonomicrosurgery for VFN is a safe therapy for voice improvement in both PVU and NVU who do not respond to voice therapy alone. Top-level artistic capabilities in PVU were restored, but numeric changes of most vocal parameters were considerably larger in NVU.

  13. Interactive Augmentation of Voice Quality and Reduction of Breath Airflow in the Soprano Voice.

    Science.gov (United States)

    Rothenberg, Martin; Schutte, Harm K

    2016-11-01

    In 1985, at a conference sponsored by the National Institutes of Health, Martin Rothenberg first described a form of nonlinear source-tract acoustic interaction mechanism by which some sopranos, singing in their high range, can use to reduce the total airflow, to allow holding the note longer, and simultaneously enrich the quality of the voice, without straining the voice. (M. Rothenberg, "Source-Tract Acoustic Interaction in the Soprano Voice and Implications for Vocal Efficiency," Fourth International Conference on Vocal Fold Physiology, New Haven, Connecticut, June 3-6, 1985.) In this paper, we describe additional evidence for this type of nonlinear source-tract interaction in some soprano singing and describe an analogous interaction phenomenon in communication engineering. We also present some implications for voice research and pedagogy. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  14. Implicit multisensory associations influence voice recognition.

    Directory of Open Access Journals (Sweden)

    Katharina von Kriegstein

    2006-10-01

    Full Text Available Natural objects provide partially redundant information to the brain through different sensory modalities. For example, voices and faces both give information about the speech content, age, and gender of a person. Thanks to this redundancy, multimodal recognition is fast, robust, and automatic. In unimodal perception, however, only part of the information about an object is available. Here, we addressed whether, even under conditions of unimodal sensory input, crossmodal neural circuits that have been shaped by previous associative learning become activated and underpin a performance benefit. We measured brain activity with functional magnetic resonance imaging before, while, and after participants learned to associate either sensory redundant stimuli, i.e. voices and faces, or arbitrary multimodal combinations, i.e. voices and written names, ring tones, and cell phones or brand names of these cell phones. After learning, participants were better at recognizing unimodal auditory voices that had been paired with faces than those paired with written names, and association of voices with faces resulted in an increased functional coupling between voice and face areas. No such effects were observed for ring tones that had been paired with cell phones or names. These findings demonstrate that brief exposure to ecologically valid and sensory redundant stimulus pairs, such as voices and faces, induces specific multisensory associations. Consistent with predictive coding theories, associative representations become thereafter available for unimodal perception and facilitate object recognition. These data suggest that for natural objects effective predictive signals can be generated across sensory systems and proceed by optimization of functional connectivity between specialized cortical sensory modules.

  15. Effect of Antenna Type on the Capacity of Body-to-Body Capacity When Using Uniform Power Allocation

    KAUST Repository

    Ghanem, Khalida; Al-Quwaiee, Hessa; Khan, Imdad; Hall, Peter

    2012-01-01

    Body-area networks are led to target multimedia applications where high-data rate is involved. In this paper, the characterization of the measured body-to-body channels and the ergodic capacity with uniform power allocation is discussed when using multiple-input multiple-output (MIMO) PIFA and IFA antenna systems. This capacity is compared to the measured belt-head and belt-chest on-body channels using PIFA antennas in the same environment. It is shown that body channels reach less ergodic capacity than the equivalent Rayleigh channel because of the presence of a LOS component. The capacity is the same for the body-to-body case regardless of the antenna and the on-body channels reach better capacity values compared to these former. © 2012 IEEE.

  16. Effect of Antenna Type on the Capacity of Body-to-Body Capacity When Using Uniform Power Allocation

    KAUST Repository

    Ghanem, Khalida

    2012-09-01

    Body-area networks are led to target multimedia applications where high-data rate is involved. In this paper, the characterization of the measured body-to-body channels and the ergodic capacity with uniform power allocation is discussed when using multiple-input multiple-output (MIMO) PIFA and IFA antenna systems. This capacity is compared to the measured belt-head and belt-chest on-body channels using PIFA antennas in the same environment. It is shown that body channels reach less ergodic capacity than the equivalent Rayleigh channel because of the presence of a LOS component. The capacity is the same for the body-to-body case regardless of the antenna and the on-body channels reach better capacity values compared to these former. © 2012 IEEE.

  17. Cross-channel effects of vocal and physical attractiveness and their implications for interpersonal perception.

    Science.gov (United States)

    Zuckerman, M; Miyake, K; Hodgins, H S

    1991-04-01

    Judges' ratings of senders' vocal attractiveness from face-plus-voice (F+V) cues were influenced by senders' physical attractiveness, and ratings of senders' physical attractiveness from F+V cues were influenced by senders' vocal attractiveness. This occurred even when judges were warned not to pay attention to face when rating vocal attractiveness and not to pay attention to voice when rating physical attractiveness. Instructions to judge attractiveness without being told which channel to attend to resulted in ratings influenced by both vocal and physical attractiveness of senders. Because of cross-channel effects, F+V attractiveness ratings should be more highly related to F+V personality impressions than attractiveness ratings based on only face or only voice. The results supported this hypothesis. Implications of cross-channel effects for research on the attractiveness stereotype were discussed.

  18. Outage capacity of multicarrier systems

    KAUST Repository

    Yilmaz, Ferkan

    2010-01-01

    The probability density function and the cumulative distribution function of the product of shifted Gamma variates are obtained in terms of the generalized Fox\\'s H function. Using these new results, the exact outage capacity of multi carrier transmission through a slow Nakagami-m fading channel is presented. Moreover, it is shown that analytical and simulation results are in perfect agreement. © 2009 IEEE.

  19. Voice and Narrative in L1 Writing

    DEFF Research Database (Denmark)

    Krogh, Ellen; Piekut, Anke

    2015-01-01

    This paper investigates issues of voice and narrative in L1 writing. Three branches of research are initial-ly discussed: research on narratives as resources for identity work, research on writer identity and voice as an essential aspect of identity, and research on Bildung in L1 writing. Subsequ...... training of voice and narratives as a resource for academic writing, and that the Bildung potential of L1 writing may be tied to this issue.......This paper investigates issues of voice and narrative in L1 writing. Three branches of research are initial-ly discussed: research on narratives as resources for identity work, research on writer identity and voice as an essential aspect of identity, and research on Bildung in L1 writing...... in lower secondary L1, she found that her previous writing strategies were not rewarded in upper secondary school. In the second empiri-cal study, two upper-secondary exam papers are investigated, with a focus on their approaches to exam genres and their use of narrative resources to address issues...

  20. Probing echoic memory with different voices.

    Science.gov (United States)

    Madden, D J; Bastian, J

    1977-05-01

    Considerable evidence has indicated that some acoustical properties of spoken items are preserved in an "echoic" memory for approximately 2 sec. However, some of this evidence has also shown that changing the voice speaking the stimulus items has a disruptive effect on memory which persists longer than that of other acoustical variables. The present experiment examined the effect of voice changes on response bias as well as on accuracy in a recognition memory task. The task involved judging recognition probes as being present in or absent from sets of dichotically presented digits. Recognition of probes spoken in the same voice as that of the dichotic items was more accurate than recognition of different-voice probes at each of three retention intervals of up to 4 sec. Different-voice probes increased the likelihood of "absent" responses, but only up to a 1.4-sec delay. These shifts in response bias may represent a property of echoic memory which should be investigated further.

  1. Channel Power in Multi-Channel Environments

    NARCIS (Netherlands)

    M.G. Dekimpe (Marnik); B. Skiera (Bernd)

    2004-01-01

    textabstractIn the literature, little attention has been paid to instances where companies add an Internet channel to their direct channel portfolio. However, actively managing multiple sales channels requires knowing the customers’ channel preferences and the resulting channel power. Two key

  2. Teachers’ voice use in teaching environment. Aspects on speakers’ comfort

    DEFF Research Database (Denmark)

    Lyberg-Åhlander, Viveka; Rydell, Roland; Löfqvist, Anders

    2015-01-01

    use and prevalence of voice problems in teachers and to explore their ratings of vocally loading aspects of their working environment. Method: A questionnaire-survey in 467 teachers aiming to explore the prevalence of voice problems in teaching staff identified teachers with voice problems and vocally...... in the teaching environment and aspects of the classroom environment were also measured. Results: Teachers with voice problems were more affected by any loading factor in the work-environment and were more perceptive of the room acoustics. Differences between the groups were found during field......-measurements of the voice, while there were no differences in the findings from the clinical examinations of larynx and voice. Conclusion: Teachers suffering from voice problems react stronger to loading factors in the teaching environment. It is in the interplay between the individual and the work environment that voice...

  3. Practical applications of interactive voice technologies: Some accomplishments and prospects

    Science.gov (United States)

    Grady, Michael W.; Hicklin, M. B.; Porter, J. E.

    1977-01-01

    A technology assessment of the application of computers and electronics to complex systems is presented. Three existing systems which utilize voice technology (speech recognition and speech generation) are described. Future directions in voice technology are also described.

  4. Voice-activated intelligent radiologic image display

    International Nuclear Information System (INIS)

    Fisher, P.

    1989-01-01

    The authors present a computer-based expert computer system called Mammo-Icon, which automatically assists the radiologist's case analysis by reviewing the trigger phrase output of a commercially available voice transcription system in he domain of mammography. A commercially available PC-based voice dictation system is coupled to an expert system implemented on a microcomputer. Software employs the LISP and C computer languages. Mammo-Icon responds to the trigger phrase output of a voice dictation system with a textual discussion of the potential significance of the findings that have been described and a display of reference images that may help the radiologist to confirm a suspected diagnosis or consider additional diagnoses. This results in automatic availability of potentially useful computer-based expert advice, making such systems much more likely to be used in routine clinical practice

  5. Effects of Voice on Emotional Arousal

    Directory of Open Access Journals (Sweden)

    Psyche eLoui

    2013-10-01

    Full Text Available Music is a powerful medium capable of eliciting a broad range of emotions. Although the relationship between language and music is well documented, relatively little is known about the effects of lyrics and the voice on the emotional processing of music and on listeners’ preferences. In the present study, we investigated the effects of vocals in music on participants’ perceived valence and arousal in songs. Participants (N = 50 made valence and arousal ratings for familiar songs that were presented with and without the voice. We observed robust effects of vocal content on perceived arousal. Furthermore, we found that the effect of the voice on enhancing arousal ratings is independent of familiarity of the song and differs across genders and age: females were more influenced by vocals than males; furthermore these gender effects were enhanced among older adults. Results highlight the effects of gender and aging in emotion perception and are discussed in terms of the social roles of music.

  6. The Study of Application System for Small and Medium CTI Based on Voice Card

    Directory of Open Access Journals (Sweden)

    Zhong Dong

    2016-01-01

    Full Text Available With the rapid development of computer telecommunications integration (CTI technology, the development of application system for small and medium CTI are updated constantly, but the study of application system for small and medium CTI, we are lack of a stability and unified model. In this paper, the author analyzes the unified structure platform of application system for small and medium CTI based on voice card. Meanwhile, the author introduces a suitable software architecture model and general procedural framework for application system for small and medium CTI based on voice card by using the idea of hierarchical design, which shows the versatility of the architecture. It provided an efficient channel for the development of small and medium CTI.

  7. A Voice Processing Technology for Rural Specific Context

    Science.gov (United States)

    He, Zhiyong; Zhang, Zhengguang; Zhao, Chunshen

    Durian the promotion and applications of rural information, different geographical dialect voice interaction is a very complex issue. Through in-depth analysis of TTS core technologies, this paper presents the methods of intelligent segmentation, word segmentation algorithm and intelligent voice thesaurus construction in the different dialects context. And then COM based development methodology for specific context voice processing system implementation and programming method. The method has a certain reference value for the rural dialect and voice processing applications.

  8. Measurement of Voice Onset Time in Maxillectomy Patients

    OpenAIRE

    Hattori, Mariko; Sumita, Yuka I.; Taniguchi, Hisashi

    2014-01-01

    Objective speech evaluation using acoustic measurement is needed for the proper rehabilitation of maxillectomy patients. For digital evaluation of consonants, measurement of voice onset time is one option. However, voice onset time has not been measured in maxillectomy patients as their consonant sound spectra exhibit unique characteristics that make the measurement of voice onset time challenging. In this study, we established criteria for measuring voice onset time in maxillectomy patients ...

  9. Influence of Smartphones and Software on Acoustic Voice Measures.

    OpenAIRE

    Elizabeth U. Grillo; Jenna N. Brosious; Staci L. Sorrell; Supraja Anand

    2016-01-01

    This study assessed the within-subject variability of voice measures captured using different recording devices (i.e., smartphones and head mounted microphone) and software programs (i.e., Analysis of Dysphonia in Speech and Voice (ADSV), Multi-dimensional Voice Program (MDVP), and Praat).  Correlations between the software programs that calculated the voice measures were also analyzed.  Results demonstrated no significant within-subject variability across devices and software and that some o...

  10. Information transfer through quantum channels

    International Nuclear Information System (INIS)

    Kretschmann, D.

    2007-01-01

    This PhD thesis represents work done between Aug. 2003 and Dec. 2006 in Reinhard F. Werner's quantum information theory group at Technische Universitaet Braunschweig, and Artur Ekert's Centre for Quantum Computation at the University of Cambridge. My thesis falls into the field of abstract quantum information theory. This work investigates both fundamental properties of quantum channels and their asymptotic capacities for classical as well as quantum information transfer. Stinespring's theorem is the basic structure theorem for quantum channels. It implies that every quantum channel can be represented as a unitary evolution on an enlarged system. In Ch. 3 we present a continuity theorem for Stinespring's representation: two quantum channels are similar if and only if it is possible to find unitary implementations that are likewise similar, with dimension-independent norm bounds. The continuity theorem allows to derive a formulation of the information-disturbance tradeoff in terms of quantum channels, and a continuity estimate for the no-broadcasting principle. In Ch. 4 we then apply the continuity theorem to give a strengthened no-go proof for quantum bit commitment, an important cryptographic primitive. This result also provides a natural characterization of those protocols that fall outside the standard setting of unconditional security, and thus may allow secure bit commitment. We present a new such protocol whose security relies on decoherence in the receiver's lab. Ch. 5 reviews the capacities of quantum channels for the transfer of both classical and quantum information, and investigates several variations in the notion of channel capacity. Memory effects are then investigated in detail in Ch. 6. We advertise a model which is sufficiently general to encompass all causal automata: every quantum process in which the outputs up to any given time t do not depend on the inputs at times t'>t can be represented as a concatenated memory channel. We then explain how

  11. Information transfer through quantum channels

    Energy Technology Data Exchange (ETDEWEB)

    Kretschmann, D.

    2007-03-12

    This PhD thesis represents work done between Aug. 2003 and Dec. 2006 in Reinhard F. Werner's quantum information theory group at Technische Universitaet Braunschweig, and Artur Ekert's Centre for Quantum Computation at the University of Cambridge. My thesis falls into the field of abstract quantum information theory. This work investigates both fundamental properties of quantum channels and their asymptotic capacities for classical as well as quantum information transfer. Stinespring's theorem is the basic structure theorem for quantum channels. It implies that every quantum channel can be represented as a unitary evolution on an enlarged system. In Ch. 3 we present a continuity theorem for Stinespring's representation: two quantum channels are similar if and only if it is possible to find unitary implementations that are likewise similar, with dimension-independent norm bounds. The continuity theorem allows to derive a formulation of the information-disturbance tradeoff in terms of quantum channels, and a continuity estimate for the no-broadcasting principle. In Ch. 4 we then apply the continuity theorem to give a strengthened no-go proof for quantum bit commitment, an important cryptographic primitive. This result also provides a natural characterization of those protocols that fall outside the standard setting of unconditional security, and thus may allow secure bit commitment. We present a new such protocol whose security relies on decoherence in the receiver's lab. Ch. 5 reviews the capacities of quantum channels for the transfer of both classical and quantum information, and investigates several variations in the notion of channel capacity. Memory effects are then investigated in detail in Ch. 6. We advertise a model which is sufficiently general to encompass all causal automata: every quantum process in which the outputs up to any given time t do not depend on the inputs at times t'>t can be represented as a concatenated memory

  12. The electronic cry: Voice and gender in electroacoustic music

    NARCIS (Netherlands)

    Bosma, H.M.

    2013-01-01

    The voice provides an entrance to discuss gender and related fundamental issues in electroacoustic music that are relevant as well in other musical genres and outside of music per se: the role of the female voice; the use of language versus non-verbal vocal sounds; the relation of voice, embodiment

  13. Original Knowledge, Gender and the Word's Mythology: Voicing the Doctorate

    Science.gov (United States)

    Carter, Susan

    2012-01-01

    Using mythology as a generative matrix, this article investigates the relationship between knowledge, words, embodiment and gender as they play out in academic writing's voice and, in particular, in doctoral voice. The doctoral thesis is defensive, a performance seeking admittance into discipline scholarship. Yet in finding its scholarly voice,…

  14. The Influence of Sleep Disorders on Voice Quality.

    Science.gov (United States)

    Rocha, Bruna Rainho; Behlau, Mara

    2017-09-19

    To verify the influence of sleep quality on the voice. Descriptive and analytical cross-sectional study. Data were collected by an online or printed survey divided in three parts: (1) demographic data and vocal health aspects; (2) self-assessment of sleep and vocal quality, and the influence that sleep has on voice; and (3) sleep and voice self-assessment inventories-the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index (PSQI), and the Voice Handicap Index reduced version (VHI-10). A total of 862 people were included (493 women, 369 men), with a mean age of 32 years old (maximum age of 79 and minimum age of 18 years old). The perception of the influence that sleep has on voice showed a difference (P influence a voice handicap are vocal self-assessment, ESS total score, and self-assessment of the influence that sleep has on voice. The absence of daytime sleepiness is a protective factor (odds ratio [OR] > 1) against perceived voice handicap; the presence of daytime sleepiness is a damaging factor (OR influences voice. Perceived poor sleep quality is related to perceived poor vocal quality. Individuals with a voice handicap observe a greater influence of sleep on voice than those without. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  15. Acoustic Analysis of Voice in Singers: A Systematic Review

    Science.gov (United States)

    Gunjawate, Dhanshree R.; Ravi, Rohit; Bellur, Rajashekhar

    2018-01-01

    Purpose: Singers are vocal athletes having specific demands from their voice and require special consideration during voice evaluation. Presently, there is a lack of standards for acoustic evaluation in them. The aim of the present study was to systematically review the available literature on the acoustic analysis of voice in singers. Method: A…

  16. Voice Disorders in Occupations with Vocal Load in Slovenia.

    Science.gov (United States)

    Boltežar, Lučka; Šereg Bahar, Maja

    2014-12-01

    The aim of this paper is to compare the prevalence of voice disorders and the risk factors for them in different occupations with a vocal load in Slovenia. A meta-analysis of six different Slovenian studies involving teachers, physicians, salespeople, catholic priests, nurses and speech-and-language therapists (SLTs) was performed. In all six studies, similar questions about the prevalence of voice disorders and the causes for them were included. The comparison of the six studies showed that more than 82% of the 2347 included subjects had voice problems at some time during their career. The teachers were the most affected by voice problems. The prevalent cause of voice problems was the vocal load in teachers and salespeople and respiratory-tract infections in all the other occupational groups. When the occupational groups were compared, it was stated that the teachers had more voice problems and showed less care for their voices than the priests. The physicians had more voice problems and showed better consideration of vocal hygiene rules than the SLTs. The majority of all the included subjects did not receive instructions about voice care during education. In order to decrease the prevalence of voice disorders in vocal professionals, a screening program is recommended before the beginning of their studies. Regular courses on voice care and proper vocal technique should be obligatory for all professional voice users during their career. The inclusion of dysphonia in the list of occupational diseases should be considered in Slovenia as it is in some European countries.

  17. The Voice Pump: an Affectively Engaging Interface for Changing Attachments

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Jacobsen, Mogens

    2017-01-01

    In this paper, we present the preliminary results from an ongoing interaction design experiment, the Voice Pump. The Voice Pump is an affectively engaging air-based interface for attuning to the differential qualities of voices in order to change attachments between native Danish speakers and non-native...

  18. The relation of vocal fold lesions and voice quality to voice handicap and psychosomatic well-being

    NARCIS (Netherlands)

    Smits, R.; Marres, H.A.; de Jong, F.

    2012-01-01

    BACKGROUND: Voice disorders have a multifactorial genesis and may be present in various ways. They can cause a significant communication handicap and impaired quality of life. OBJECTIVE: To assess the effect of vocal fold lesions and voice quality on voice handicap and psychosomatic well-being.

  19. Voice Activated Cockpit Management Systems: Voice-Flight NexGen, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Speaking to the cockpit as a method of system management in flight can become an effective interaction method, since voice communication is very efficient. Automated...

  20. Voice Over Internet Protocol Testbed Design for Non-Intrusive, Objective Voice Quality Assessment

    National Research Council Canada - National Science Library

    Manka, David L

    2007-01-01

    Voice over Internet Protocol (VoIP) is an emerging technology with the potential to assist the United States Marine Corps in solving communication challenges stemming from modern operational concepts...

  1. Obligatory and facultative brain regions for voice-identity recognition

    Science.gov (United States)

    Roswandowitz, Claudia; Kappes, Claudia; Obrig, Hellmuth; von Kriegstein, Katharina

    2018-01-01

    Abstract Recognizing the identity of others by their voice is an important skill for social interactions. To date, it remains controversial which parts of the brain are critical structures for this skill. Based on neuroimaging findings, standard models of person-identity recognition suggest that the right temporal lobe is the hub for voice-identity recognition. Neuropsychological case studies, however, reported selective deficits of voice-identity recognition in patients predominantly with right inferior parietal lobe lesions. Here, our aim was to work towards resolving the discrepancy between neuroimaging studies and neuropsychological case studies to find out which brain structures are critical for voice-identity recognition in humans. We performed a voxel-based lesion-behaviour mapping study in a cohort of patients (n = 58) with unilateral focal brain lesions. The study included a comprehensive behavioural test battery on voice-identity recognition of newly learned (voice-name, voice-face association learning) and familiar voices (famous voice recognition) as well as visual (face-identity recognition) and acoustic control tests (vocal-pitch and vocal-timbre discrimination). The study also comprised clinically established tests (neuropsychological assessment, audiometry) and high-resolution structural brain images. The three key findings were: (i) a strong association between voice-identity recognition performance and right posterior/mid temporal and right inferior parietal lobe lesions; (ii) a selective association between right posterior/mid temporal lobe lesions and voice-identity recognition performance when face-identity recognition performance was factored out; and (iii) an association of right inferior parietal lobe lesions with tasks requiring the association between voices and faces but not voices and names. The results imply that the right posterior/mid temporal lobe is an obligatory structure for voice-identity recognition, while the inferior parietal

  2. Epidemiology of Voice Disorders in Latvian School Teachers.

    Science.gov (United States)

    Trinite, Baiba

    2017-07-01

    The prevalence of voice disorders in the teacher population in Latvia has not been studied so far and this is the first epidemiological study whose goal is to investigate the prevalence of voice disorders and their risk factors in this professional group. A wide cross-sectional study using stratified sampling methodology was implemented in the general education schools of Latvia. The self-administered voice risk factor questionnaire and the Voice Handicap Index were completed by 522 teachers. Two teachers groups were formed: the voice disorders group which included 235 teachers with actual voice problems or problems during the last 9 months; and the control group which included 174 teachers without voice disorders. Sixty-six percent of teachers gave a positive answer to the following question: Have you ever had problems with your voice? Voice problems are more often found in female than male teachers (68.2% vs 48.8%). Music teachers suffer from voice disorders more often than teachers of other subjects. Eighty-two percent of teachers first faced voice problems in their professional carrier. The odds of voice disorders increase if the following risk factors exist: extra vocal load, shouting, throat clearing, neglecting of personal health, background noise, chronic illnesses of the upper respiratory tract, allergy, job dissatisfaction, and regular stress in the working place. The study findings indicated a high risk of voice disorders among Latvian teachers. The study confirmed data concerning the multifactorial etiology of voice disorders. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  3. The capacity of black holes to transmit quantum information

    International Nuclear Information System (INIS)

    Brádler, Kamil; Adami, Christoph

    2014-01-01

    We study the properties of the quantum information transmission channel that emerges from the quantum dynamics of particles interacting with a black hole horizon. We calculate the quantum channel capacity in two limiting cases where a single-letter capacity is known to exist: the limit of perfectly reflecting and perfectly absorbing black holes. We find that the perfectly reflecting black hole channel is closely related to the Unruh channel and that its capacity is non-vanishing, allowing for the perfect reconstruction of quantum information outside of the black hole horizon. We also find that the complementary channel (transmitting entanglement behind the horizon) is entanglement-breaking in this case, with vanishing capacity. We then calculate the quantum capacity of the black hole channel in the limit of a perfectly absorbing black hole and find that this capacity vanishes, while the capacity of the complementary channel is non-vanishing instead. Rather than inviting a new crisis for quantum physics, this finding instead is in accordance with the quantum no-cloning theorem, because it guarantees that there are no space-like surfaces that contain both the sender’s quantum state and the receiver’s reconstructed quantum state

  4. The capacity of black holes to transmit quantum information

    Energy Technology Data Exchange (ETDEWEB)

    Brádler, Kamil [Department of Astronomy and Physics, Saint Mary’s University,Halifax, Nova Scotia, B3H 3C3 (Canada); Adami, Christoph [Department of Physics and Astronomy, Michigan State University,East Lansing, MI 48824 (United States)

    2014-05-21

    We study the properties of the quantum information transmission channel that emerges from the quantum dynamics of particles interacting with a black hole horizon. We calculate the quantum channel capacity in two limiting cases where a single-letter capacity is known to exist: the limit of perfectly reflecting and perfectly absorbing black holes. We find that the perfectly reflecting black hole channel is closely related to the Unruh channel and that its capacity is non-vanishing, allowing for the perfect reconstruction of quantum information outside of the black hole horizon. We also find that the complementary channel (transmitting entanglement behind the horizon) is entanglement-breaking in this case, with vanishing capacity. We then calculate the quantum capacity of the black hole channel in the limit of a perfectly absorbing black hole and find that this capacity vanishes, while the capacity of the complementary channel is non-vanishing instead. Rather than inviting a new crisis for quantum physics, this finding instead is in accordance with the quantum no-cloning theorem, because it guarantees that there are no space-like surfaces that contain both the sender’s quantum state and the receiver’s reconstructed quantum state.

  5. Engaging retailers: giving them voice or controlling their voice, a supplier's perspective

    OpenAIRE

    Jackson, Keith; Jackson, Jacqui; Hopkinson, Gillian

    2013-01-01

    This full paper from the Marketing and Retail track of BAM 2013 investigates the relationships between suppliers and retailers in the UK convenience store sector in terms of Hirschman's model whereby members of a group can influence it by either expressing their opinions (voice) or leaving it in protest (exit). Suppliers may create loyalty among retailers by raising exit costs and/or allowing them to express their voices. The investigation was carried out using the recorded turnover of the to...

  6. Voice Onset Time in Parkinson Disease

    Science.gov (United States)

    Fischer, Emily; Goberman, Alexander M.

    2010-01-01

    Research has found that speaking rate has an effect on voice onset time (VOT). Given that Parkinson disease (PD) affects speaking rate, the purpose of this study was to examine VOT with the effect of rate removed (VOT ratio), along with the traditional VOT measure, in individuals with PD. VOT and VOT ratio were examined in 9 individuals with PD…

  7. Classroom Noise and Teachers' Voice Production

    Science.gov (United States)

    Rantala, Leena M.; Hakala, Suvi; Holmqvist, Sofia; Sala, Eeva

    2015-01-01

    Purpose: The aim of this study was to research the associations between noise (ambient and activity noise) and objective metrics of teachers' voices in real working environments (i.e., classrooms). Method: Thirty-two female and 8 male teachers from 14 elementary schools were randomly selected for the study. Ambient noise was measured during breaks…

  8. Student Voice Initiative: Exploring Implementation Strategies

    Science.gov (United States)

    Alexander, Blaine G.

    2017-01-01

    Student voice is the process of allowing students to work collaboratively with adults to produce a learning culture that is conducive for optimum growth in every student. In a traditional setting, the adults make the decisions and the students are passive observers in the learning process. Data has shown that this traditional culture is not…

  9. Developing Student Voices on the Internet.

    Science.gov (United States)

    Dresang, Eliza T.

    1997-01-01

    Books and online discussion groups encourage youth to develop strong narrative voices. Includes an annotated bibliography of books and Internet sites dealing with discovering the self and others; exploring race, culture, archeology, technology, war, poverty, gender and urban problems; creating and critiquing stories; and publishing industry…

  10. Speech masking and cancelling and voice obscuration

    Science.gov (United States)

    Holzrichter, John F.

    2013-09-10

    A non-acoustic sensor is used to measure a user's speech and then broadcasts an obscuring acoustic signal diminishing the user's vocal acoustic output intensity and/or distorting the voice sounds making them unintelligible to persons nearby. The non-acoustic sensor is positioned proximate or contacting a user's neck or head skin tissue for sensing speech production information.

  11. Web life: Voices of the Manhattan Project

    Science.gov (United States)

    2014-02-01

    Voices of the Manhattan Project was launched in October 2012 with the aim of preserving the memories and experiences of scientists and other workers who participated in the US-led effort to build an atomic bomb during the Second World War.

  12. Ventriloquising the Voice: Writing in the University

    Science.gov (United States)

    Fulford, Amanda

    2009-01-01

    In this paper I consider one aspect of how student writing is supported in the university. I focus on the use of the "writing frame", questioning its status as a vehicle for facilitating student voice, and in the process questioning how that notion is itself understood. I illustrate this by using examples from the story of the 1944 Hollywood film…

  13. Voice Recognition in Face-Blind Patients

    Science.gov (United States)

    Liu, Ran R.; Pancaroglu, Raika; Hills, Charlotte S.; Duchaine, Brad; Barton, Jason J. S.

    2016-01-01

    Right or bilateral anterior temporal damage can impair face recognition, but whether this is an associative variant of prosopagnosia or part of a multimodal disorder of person recognition is an unsettled question, with implications for cognitive and neuroanatomic models of person recognition. We assessed voice perception and short-term recognition of recently heard voices in 10 subjects with impaired face recognition acquired after cerebral lesions. All 4 subjects with apperceptive prosopagnosia due to lesions limited to fusiform cortex had intact voice discrimination and recognition. One subject with bilateral fusiform and anterior temporal lesions had a combined apperceptive prosopagnosia and apperceptive phonagnosia, the first such described case. Deficits indicating a multimodal syndrome of person recognition were found only in 2 subjects with bilateral anterior temporal lesions. All 3 subjects with right anterior temporal lesions had normal voice perception and recognition, 2 of whom performed normally on perceptual discrimination of faces. This confirms that such lesions can cause a modality-specific associative prosopagnosia. PMID:25349193

  14. Changes after voice therapy in objective and subjective voice measurements of pediatric patients with vocal nodules.

    Science.gov (United States)

    Tezcaner, Ciler Zahide; Karatayli Ozgursoy, Selmin; Ozgursoy, Selmin Karatayli; Sati, Isil; Dursun, Gursel

    2009-12-01

    The aim of this study was to analyze the efficiency of the voice therapy in children with vocal nodules by using the acoustic analysis and subjective assessment. Thirty-nine patients with vocal fold nodules, aged between 7 and 14, were included in the study. Each subject had voice therapy led by an experienced voice therapist once a week. All diagnostic and follow-up workouts were performed before the voice therapy and after the third or the sixth month. Transoral and/or transnasal videostroboscopic examination and acoustic analysis were achieved using multi-dimensional voice program (MDVP) and subjective analysis with GRBAS scale. As for the perceptual assessment, the difference was significant for four parameters out of five. A significant improvement was found in the acoustic analysis parameters of jitter, shimmer, and noise-to-harmonic ratio. The voice therapy which was planned according to patients' needs, age, compliance and response to therapy had positive effects on pediatric patients with vocal nodules. Acoustic analysis and GRBAS may be used successfully in the follow-up of pediatric vocal nodule treatment.

  15. The Sound of Voice: Voice-Based Categorization of Speakers' Sexual Orientation within and across Languages.

    Directory of Open Access Journals (Sweden)

    Simone Sulpizio

    Full Text Available Empirical research had initially shown that English listeners are able to identify the speakers' sexual orientation based on voice cues alone. However, the accuracy of this voice-based categorization, as well as its generalizability to other languages (language-dependency and to non-native speakers (language-specificity, has been questioned recently. Consequently, we address these open issues in 5 experiments: First, we tested whether Italian and German listeners are able to correctly identify sexual orientation of same-language male speakers. Then, participants of both nationalities listened to voice samples and rated the sexual orientation of both Italian and German male speakers. We found that listeners were unable to identify the speakers' sexual orientation correctly. However, speakers were consistently categorized as either heterosexual or gay on the basis of how they sounded. Moreover, a similar pattern of results emerged when listeners judged the sexual orientation of speakers of their own and of the foreign language. Overall, this research suggests that voice-based categorization of sexual orientation reflects the listeners' expectations of how gay voices sound rather than being an accurate detector of the speakers' actual sexual identity. Results are discussed with regard to accuracy, acoustic features of voices, language dependency and language specificity.

  16. Perceiving a stranger's voice as being one's own: a 'rubber voice' illusion?

    Directory of Open Access Journals (Sweden)

    Zane Z Zheng

    2011-04-01

    Full Text Available We describe an illusion in which a stranger's voice, when presented as the auditory concomitant of a participant's own speech, is perceived as a modified version of their own voice. When the congruence between utterance and feedback breaks down, the illusion is also broken. Compared to a baseline condition in which participants heard their own voice as feedback, hearing a stranger's voice induced robust changes in the fundamental frequency (F0 of their production. Moreover, the shift in F0 appears to be feedback dependent, since shift patterns depended reliably on the relationship between the participant's own F0 and the stranger-voice F0. The shift in F0 was evident both when the illusion was present and after it was broken, suggesting that auditory feedback from production may be used separately for self-recognition and for vocal motor control. Our findings indicate that self-recognition of voices, like other body attributes, is malleable and context dependent.

  17. Site-Specific Soundscape Design for the Creation of Sonic Architectures and the Emergent Voices of Buildings

    Directory of Open Access Journals (Sweden)

    Jordan Lacey

    2014-01-01

    Full Text Available Does a building contain its own Voice? And if so, can that Voice be discovered, transformed and augmented by soundscape design? Barry Blesser’s writings on acoustic space, discuss reverberation and resonant frequencies as providing architectural spaces with characteristic listening conditions related to the architectural space’s dimensions and materiality. The paper argues that Blesser and Salter expand such discussion into pantheistic speculation when suggesting that humanity contains the imaginative capacity to experience spaces as “living spirits”. This argument is achieved by building on the speculation through the discussion of a soundscape design methodology that considers space as containing pantheistic qualities. Sonic architectures are created with electroacoustic sound installations that recompose existing architectural soundscapes, to create the conditions for the emergence of the Voices of buildings. This paper describes two soundscape designs, Revoicing the Striated Soundscape and Subterranean Voices, which transformed existing architectural soundscapes for the emergence of Voices in a laneway and a building located in the City of Melbourne, Australia.

  18. Channelling and electromagnetic radiation of channelling particles

    International Nuclear Information System (INIS)

    Kalashnikov, N.

    1983-01-01

    A brief description is presented of the channelling of charged particles between atoms in the crystal lattice. The specificities are discussed of the transverse motion of channelling particles as are the origin and properties of quasi-characteristic radiation of channelling particles which accompany transfers from one band of permissible energies of the transverse motion of channelling particles to the other. (B.S.)

  19. Self-Reported Acute and Chronic Voice Disorders in Teachers.

    Science.gov (United States)

    Rossi-Barbosa, Luiza Augusta Rosa; Barbosa, Mirna Rossi; Morais, Renata Martins; de Sousa, Kamilla Ferreira; Silveira, Marise Fagundes; Gama, Ana Cristina Côrtes; Caldeira, Antônio Prates

    2016-11-01

    The present study aimed to identify factors associated with self-reported acute and chronic voice disorders among municipal elementary school teachers in the city of Montes Claros, in the State of Minas Gerais, Brazil. The dependent variable, self-reported dysphonia, was determined via a single question, "Have you noticed changes in your voice quality?" and if so, a follow-up question queried the duration of this change, acute or chronic. The independent variables were dichotomized and divided into five categories: sociodemographic and economic data; lifestyle; organizational and environmental data; health-disease processes; and voice. Analyses of associated factors were performed via a hierarchical multiple logistic regression model. The present study included 226 teachers, of whom 38.9% reported no voice disorders, 35.4% reported an acute disorder, and 25.7% reported a chronic disorder. Excessive voice use daily, consuming more than one alcoholic drink per time, and seeking medical treatment because of voice disorders were associated factors for acute and chronic voice disorders. Consuming up to three glasses of water per day was associated with acute voice disorders. Among teachers who reported chronic voice disorders, teaching for over 15 years and the perception of disturbing or unbearable noise outside the school were both associated factors. Identification of organizational, environmental, and predisposing risk factors for voice disorders is critical, and furthermore, a vocal health promotion program may address these issues. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  20. Quantum capacity of quantum black holes

    Science.gov (United States)

    Adami, Chris; Bradler, Kamil

    2014-03-01

    The fate of quantum entanglement interacting with a black hole has been an enduring mystery, not the least because standard curved space field theory does not address the interaction of black holes with matter. We discuss an effective Hamiltonian of matter interacting with a black hole that has a precise analogue in quantum optics and correctly reproduces both spontaneous and stimulated Hawking radiation with grey-body factors. We calculate the quantum capacity of this channel in the limit of perfect absorption, as well as in the limit of a perfectly reflecting black hole (a white hole). We find that the white hole is an optimal quantum cloner, and is isomorphic to the Unruh channel with positive quantum capacity. The complementary channel (across the horizon) is entanglement-breaking with zero capacity, avoiding a violation of the quantum no-cloning theorem. The black hole channel on the contrary has vanishing capacity, while its complement has positive capacity instead. Thus, quantum states can be reconstructed faithfully behind the black hole horizon, but not outside. This work sheds new light on black hole complementarity because it shows that black holes can both reflect and absorb quantum states without violating the no-cloning theorem, and makes quantum firewalls obsolete.

  1. Alexa, Siri, Cortana, and More: An Introduction to Voice Assistants.

    Science.gov (United States)

    Hoy, Matthew B

    2018-01-01

    Voice assistants are software agents that can interpret human speech and respond via synthesized voices. Apple's Siri, Amazon's Alexa, Microsoft's Cortana, and Google's Assistant are the most popular voice assistants and are embedded in smartphones or dedicated home speakers. Users can ask their assistants questions, control home automation devices and media playback via voice, and manage other basic tasks such as email, to-do lists, and calendars with verbal commands. This column will explore the basic workings and common features of today's voice assistants. It will also discuss some of the privacy and security issues inherent to voice assistants and some potential future uses for these devices. As voice assistants become more widely used, librarians will want to be familiar with their operation and perhaps consider them as a means to deliver library services and materials.

  2. Designing a Voice Controlled Interface For Radio : Guidelines for The First Generation of Voice Controlled Public Radio

    OpenAIRE

    Päärni, Anna

    2017-01-01

    From being a fictional element in sci-fi, voice control has become a reality, with inventions such as Apple's Siri, and interactive voice response (IVR) when calling your doctor's office. The combination of radio’s strength as a hands-free medium, public radio’s mission to reach across all platforms and the rise of voice makes up a relevant intersection; voice controlled public radio in Sweden. This thesis has aimed to investigate how radio listeners wish to interact using voice control to li...

  3. Channeling experiment

    International Nuclear Information System (INIS)

    Abelin, H.; Birgersson, L.; Widen, H.; Aagren, T.; Moreno, L.; Neretnieks, I.

    1990-07-01

    Channeling of water flow and tracer transport in real fractures in a granite body at Stripa have been investigated experimentally. The experimental site was located 360 m below the ground level. Two kinds of experiments were performed. In the single hole experiments, 20 cm diameter holes were drilled about 2.5 m into the rock in the plane of the fracture. Specially designed packers were used to inject water into the fracture in 5 cm intervals all along the fracture trace in the hole. The variation of the injection flowrates along the fracture were used to determine the transmissivity variations in the fracture plane. Detailed photographs were taken from inside the hole and the visual fracture aperture was compared with the injection flowrates in the same locations. Geostatistical methods were used to evaluate the results. Five holes were measured in great detail. In addition 7 holes were drilled and scanned by simpler packer systems. A double hole experiment was performed where two parallel holes were drilled in the same fracture plane at nearly 2 m distance. Pressure pulse tests were made between the holes in both directions. Tracers were injected in 5 locations in one hole and monitored for in many locations in the other hole. The single hole experiment and the double hole experiment show that most of the fracture planes are tight but that there are open sections which form connected channels over distances of at least 2 meters. It was also found in the double hole experiment that the investigated fracture was intersected by at least one fracture between the two holes which diverted a large amount of the injected tracers to several distant locations at the tunnel wall. (authours)

  4. Clinical Features of Psychogenic Voice Disorder and the Efficiency of Voice Therapy and Psychological Evaluation.

    Science.gov (United States)

    Tezcaner, Zahide Çiler; Gökmen, Muhammed Fatih; Yıldırım, Sibel; Dursun, Gürsel

    2017-11-06

    The aim of this study was to define the clinical features of psychogenic voice disorder (PVD) and explore the treatment efficiency of voice therapy and psychological evaluation. Fifty-eight patients who received treatment following the PVD diagnosis and had no organic or other functional voice disorders were assessed retrospectively based on laryngoscopic examinations and subjective and objective assessments. Epidemiological characteristics, accompanying organic and psychological disorders, preferred methods of treatment, and previous treatment outcomes were examined for each patient. A comparison was made based on voice disorders and responses to treatment between patients who received psychotherapy and patients who did not. Participants in this study comprised 58 patients, 10 male and 48 female. Voice therapy was applied in all patients, 54 (93.1%) of whom had improvement in their voice. Although all patients were advised to undergo psychological assessment, only 60.3% (35/58) of them underwent psychological assessment. No statistically significant difference was found between patients who did receive psychological support concerning their treatment responses and patients who did not. Relapse occurred in 14.7% (5/34) of the patients who applied for psychological assessment and in 50% (10/20) of those who did not. There was a statistically significant difference in relapse rates, which was higher among patients who did not receive psychological support (P therapy is an efficient treatment method for PVD. However, in the long-term follow-up, relapse of the disease is observed to be higher among patients who failed to follow up on the recommendation for psychological assessment. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  5. The singer's voice range profile: female professional opera soloists.

    Science.gov (United States)

    Lamarche, Anick; Ternström, Sten; Pabon, Peter

    2010-07-01

    This work concerns the collection of 30 voice range profiles (VRPs) of female operatic voice. We address the questions: Is there a need for a singer's protocol in VRP acquisition? Are physiological measurements sufficient or should the measurement of performance capabilities also be included? Can we address the female singing voice in general or is there a case for categorizing voices when studying phonetographic data? Subjects performed a series of structured tasks involving both standard speech voice protocols and additional singing tasks. Singers also completed an extensive questionnaire. Physiological VRPs differ from performance VRPs. Two new VRP metrics, the voice area above a defined level threshold and the dynamic range independent from the fundamental frequency (F(0)), were found to be useful in the analysis of singer VRPs. Task design had no effect on performance VRP outcomes. Voice category differences were mainly attributable to phonation frequency-based information. Results support the clinical importance of addressing the vocal instrument as it is used in performance. Equally important is the elaboration of a protocol suitable for the singing voice. The given context and instructions can be more important than task design for performance VRPs. Yet, for physiological VRP recordings, task design remains critical. Both types of VRPs are suggested for a singer's voice evaluation. Copyright (c) 2010 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  6. Voice-to-Phoneme Conversion Algorithms for Voice-Tag Applications in Embedded Platforms

    Directory of Open Access Journals (Sweden)

    Yan Ming Cheng

    2008-08-01

    Full Text Available We describe two voice-to-phoneme conversion algorithms for speaker-independent voice-tag creation specifically targeted at applications on embedded platforms. These algorithms (batch mode and sequential are compared in speech recognition experiments where they are first applied in a same-language context in which both acoustic model training and voice-tag creation and application are performed on the same language. Then, their performance is tested in a cross-language setting where the acoustic models are trained on a particular source language while the voice-tags are created and applied on a different target language. In the same-language environment, both algorithms either perform comparably to or significantly better than the baseline where utterances are manually transcribed by a phonetician. In the cross-language context, the voice-tag performances vary depending on the source-target language pair, with the variation reflecting predicted phonological similarity between the source and target languages. Among the most similar languages, performance nears that of the native-trained models and surpasses the native reference baseline.

  7. [Design of standard voice sample text for subjective auditory perceptual evaluation of voice disorders].

    Science.gov (United States)

    Li, Jin-rang; Sun, Yan-yan; Xu, Wen

    2010-09-01

    To design a speech voice sample text with all phonemes in Mandarin for subjective auditory perceptual evaluation of voice disorders. The principles for design of a speech voice sample text are: The short text should include the 21 initials and 39 finals, this may cover all the phonemes in Mandarin. Also, the short text should have some meanings. A short text was made out. It had 155 Chinese words, and included 21 initials and 38 finals (the final, ê, was not included because it was rarely used in Mandarin). Also, the text covered 17 light tones and one "Erhua". The constituent ratios of the initials and finals presented in this short text were statistically similar as those in Mandarin according to the method of similarity of the sample and population (r = 0.742, P text were statistically not similar as those in Mandarin (r = 0.731, P > 0.05). A speech voice sample text with all phonemes in Mandarin was made out. The constituent ratios of the initials and finals presented in this short text are similar as those in Mandarin. Its value for subjective auditory perceptual evaluation of voice disorders need further study.

  8. Experiences with voice to design ceramics

    DEFF Research Database (Denmark)

    Hansen, Flemming Tvede; Jensen, Kristoffer

    2014-01-01

    This article presents SoundShaping, a system to create ceramics from the human voice and thus how digital technology makes new possibilities in ceramic craft. The article is about how experiential knowledge that the craftsmen gains in a direct physical and tactile interaction with a responding...... material can be transformed and utilised in the use of digital technologies. SoundShaping is based on a generic audio feature extraction system and the principal component analysis to ensure that the pertinent information in the voice is used. Moreover, 3D shape is created using simple geometric rules....... The shape is output to a 3D printer to make ceramic results. The system demonstrates the close connection between digital technology and craft practice. Several experiments and reflections demonstrate the validity of this work....

  9. Experiences with Voice to Design Ceramics

    DEFF Research Database (Denmark)

    Hansen, Flemming Tvede; Jensen, Kristoffer

    2013-01-01

    This article presents SoundShaping, a system to create ceramics from the human voice and thus how digital technology makes new possibilities in ceramic craft. The article is about how experiential knowledge that the craftsmen gains in a direct physical and tactile interaction with a responding...... material can be transformed and utilized in the use of digital technologies. SoundShaping is based on a generic audio feature extraction system and the principal component analysis to ensure that the pertinent information in the voice is used. Moreover, 3D shape is created using simple geometric rules....... The shape is output to a 3D printer to make ceramic results. The system demonstrates the close connection between digital technology and craft practice. Several experiments and reflections demonstrate the validity of this work....

  10. Speech enhancement on smartphone voice recording

    International Nuclear Information System (INIS)

    Atmaja, Bagus Tris; Farid, Mifta Nur; Arifianto, Dhany

    2016-01-01

    Speech enhancement is challenging task in audio signal processing to enhance the quality of targeted speech signal while suppress other noises. In the beginning, the speech enhancement algorithm growth rapidly from spectral subtraction, Wiener filtering, spectral amplitude MMSE estimator to Non-negative Matrix Factorization (NMF). Smartphone as revolutionary device now is being used in all aspect of life including journalism; personally and professionally. Although many smartphones have two microphones (main and rear) the only main microphone is widely used for voice recording. This is why the NMF algorithm widely used for this purpose of speech enhancement. This paper evaluate speech enhancement on smartphone voice recording by using some algorithms mentioned previously. We also extend the NMF algorithm to Kulback-Leibler NMF with supervised separation. The last algorithm shows improved result compared to others by spectrogram and PESQ score evaluation. (paper)

  11. Acoustic passaggio pedagogy for the male voice.

    Science.gov (United States)

    Bozeman, Kenneth Wood

    2013-07-01

    Awareness of interactions between the lower harmonics of the voice source and the first formant of the vocal tract, and of the passive vowel modifications that accompany them, can assist in working out a smooth transition through the passaggio of the male voice. A stable vocal tract length establishes the general location of all formants, including the higher formants that form the singer's formant cluster. Untrained males instinctively shorten the tube to preserve the strong F1/H2 acoustic coupling of voce aperta, resulting in 'yell' timbre. If tube length and shape are kept stable during pitch ascent, the yell can be avoided by allowing the second harmonic to rise above the first formant, creating the balanced timbre of voce chiusa.

  12. Digital Media Creates Youth Voices Heard

    Directory of Open Access Journals (Sweden)

    Jeff Sallee

    2014-06-01

    Full Text Available Oklahoma 4-H clubs and military service centers partnered with the Adobe Youth Voices (AYV program to give youth opportunities to raise their voices through digital media. This program reached out to underrepresented youth and gave them the tools and technology to effectively express themselves. The intent of this project was for 4-H members to create videos to educate, help and raise awareness in their communities of topics that were important to the youth. These experiences help youth gain knowledge towards helping others solve farm, home, and community problems. Participating youth selected issues that were important to them and created a short video, educating others and sharing their convictions on the topics of horse therapy, citizenship, bullying, and distracted driving.

  13. Using the Voice to Design Ceramics

    DEFF Research Database (Denmark)

    Hansen, Flemming Tvede; Jensen, Kristoffer

    2011-01-01

    Digital technology makes new possibilities in ceramic craft. This project is about how experiential knowledge that the craftsmen gains in a direct physical and tactile interaction with a responding material can be transformed and utilized in the use of digital technologies. The project presents...... to make ceramic results. The system demonstrates the close connection between digital technology and craft practice....... SoundShaping, a system to create ceramics from the human voice. Based on a generic audio feature extraction system, and the principal component analysis to ensure that the pertinent information in the voice is used, a 3D shape is created using simple geometric rules. This shape is output to a 3D printer...

  14. Audio-Visual: Disembodied Voices in Theory

    OpenAIRE

    Le Fèvre-Berthelot, Anaïs

    2013-01-01

    After a survey of the major critical trends since the generalization of synchronized film sound, this bibliographical essay sets out to delineate the way film sound studies have developed around issues of taxonomy, meaning, and reception. Focusing on the treatment of the disembodied voice by various theorists, three trends can be identified: borrowing from semiology and narratology, an essentially descriptive approach first emerges that creates a new vocabulary to talk about sound and analyze...

  15. Voice coil based scanning probe microscopy

    Czech Academy of Sciences Publication Activity Database

    Klapetek, P.; Valtr, M.; Duchoň, V.; Sobota, Jaroslav

    2012-01-01

    Roč. 7, č. 6 (2012), 332:1-7 ISSN 1931-7573 R&D Projects: GA MPO FR-TI1/241; GA AV ČR KAN311610701; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : SPM * Voice coil * Interferometry Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.524, year: 2012

  16. Effect of tonsillectomy on the adult voice.

    LENUS (Irish Health Repository)

    Heffernan, Colleen B

    2012-02-01

    OBJECTIVES AND HYPOTHESIS: Anecdotal evidence suggests that tonsillectomy has no deleterious consequences on a person\\'s voice under normal vocal demand. However, whether the enlarged dimensions of the oropharynx after tonsillectomy impair the quality of a professional voice user remains unclear. Therefore, we designed a study to determine whether adult tonsillectomy altered the resonance characteristics of the vocal tract in any way and whether these changes were transient or permanent. STUDY DESIGN: This is a prospective observational study with full institutional ethical approval. METHODS: All adult patients presenting for tonsillectomy for recurrent tonsillitis in our institution were recruited. Their voice was recorded preoperatively, postoperatively, and at 4 weeks postoperatively. The values of the first four formants were calculated in all recordings. The oropharyngeal dimensions were measured preoperatively and postoperatively. Tonsillar weights and volumes were also measured. RESULTS: The first formant was noted to rise postoperatively. The average value of F2 and F3 did not alter postoperatively or at 4 weeks. However, it was noted that the fourth formant was not universally present preoperatively but was present in all patients postoperatively and at 4 weeks. CONCLUSIONS: Altering the dimensions of the oropharynx after tonsillectomy causes the first formant to rise but has no effect on the third and fourth formants. However, the fourth formant appears in patients who previously did not demonstrate it. The fourth formant was present in a greater proportion of male patients preoperatively than female patients, but it was universally present postoperatively and at 4 weeks in both sexes. This suggests that increasing the horizontal dimensions of the oropharynx has a nontransient effect on the higher order formants of the voice.

  17. Start with the street, the voice said

    OpenAIRE

    Jobst, Marko

    2017-01-01

    This text offers a writing experiment that aims to address the processes of gentrification. It employs a narrative mode of writing in the first person plural in order to demonstrate one possible way of capturing the complexities of everyday experiences of metropolitan conditions. The text challenges the assumed notions of authorial voice and supposed analytical objectivity of (academic) critique and proposes a way of tackling the ambiguities that lie at the core of the relationship forged bet...

  18. Improving WCDMA netwotk capacity using adaptive sectorisation ...

    African Journals Online (AJOL)

    A major problem affecting the capacity of Wideband Code Division Multiple Access (WCDMA) is interference. This work focuses on reducing co-channel interference problem by the application of adaptive sectorisation in nonuniform traffic. It considers an isolated areas of congested traffic called Hot Spots (HS).

  19. Voice parameters and videonasolaryngoscopy in children with vocal nodules: a longitudinal study, before and after voice therapy.

    Science.gov (United States)

    Valadez, Victor; Ysunza, Antonio; Ocharan-Hernandez, Esther; Garrido-Bustamante, Norma; Sanchez-Valerio, Araceli; Pamplona, Ma C

    2012-09-01

    Vocal Nodules (VN) are a functional voice disorder associated with voice misuse and abuse in children. There are few reports addressing vocal parameters in children with VN, especially after a period of vocal rehabilitation. The purpose of this study is to describe measurements of vocal parameters including Fundamental Frequency (FF), Shimmer (S), and Jitter (J), videonasolaryngoscopy examination and clinical perceptual assessment, before and after voice therapy in children with VN. Voice therapy was provided using visual support through Speech-Viewer software. Twenty patients with VN were studied. An acoustical analysis of voice was performed and compared with data from subjects from a control group matched by age and gender. Also, clinical perceptual assessment of voice and videonasolaryngoscopy were performed to all patients with VN. After a period of voice therapy, provided with visual support using Speech Viewer-III (SV-III-IBM) software, new acoustical analyses, perceptual assessments and videonasolaryngoscopies were performed. Before the onset of voice therapy, there was a significant difference (ptherapy period, a significant improvement (pvocal nodules were no longer discernible on the vocal folds in any of the cases. SV-III software seems to be a safe and reliable method for providing voice therapy in children with VN. Acoustic voice parameters, perceptual data and videonasolaryngoscopy were significantly improved after the speech therapy period was completed. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  20. Voice after radiotherapy of the larynx carcinoma

    International Nuclear Information System (INIS)

    Niedzielska, Grazyna; Niedzielski, Antoni; Toman, Danuta

    2010-01-01

    Background: The study presents the evaluation of the phonatory function of the larynx after radiotherapy. The research covered the patients from the rural areas of Poland who revealed neoplastic changes in the glottis area. Material and methods: The test group consisted of 45 men aged 41-78 years with the carcinoma of the larynx with T1 and T2 progression types of cancer, according to the TNM classification. The analysis of laryngeal tone was performed with the digital analyzer Kay Elemetrics Model CSL 4300 and Multi Dimensional Voice Program (MDVP). A stroboscopic test in all the patients with T1 progression revealed the reduction of vibrations. Results: The acoustic analysis of the voice in the pre-treatment group as compared with the control group allowed for differentiation of the following parameters of a definitely pathologic character: Jita, Jitter, RAP, PPQ, vFo, Shimmer, APQ, vAm, NHR, VTI, SPI, and DUV. Conclusions: In the acoustic analysis of voice in the post-radiotherapy group, the following parameters reached values close to the norm: JITA, JITT, RAP, PPQ, vF0, vAM, DUV, and Schimmer dB.