Deliberate Signal Research Articles

Inferring Interactivity From Gaze Patterns During Triadic Person-Object-Agent Interactions.

Observing others’ gaze informs us about relevant matters in the environment. Humans’ sensitivity to gaze cues and our ability to use this information to focus our own attention is crucial to learning, social coordination, and survival. Gaze can also be a deliberate social signal which captures and directs the gaze of others toward an object of interest. In the current study, we investigated whether the intention to actively communicate one’s own attentional focus can be inferred from the dynamics of gaze alone. We used a triadic gaze interaction paradigm based on the recently proposed classification of attentional states and respective gaze patterns in person-object-person interactions, the so-called “social gaze space (SGS).” Twenty-eight participants interacted with a computer controlled virtual agent while they assumed to interact with a real human. During the experiment, the virtual agent engaged in various gaze patterns which were determined by the agent’s attentional communicative state, as described by the concept of SGS. After each interaction, participants were asked to judge whether the other person was trying to deliberately interact with them. Results show that participants were able to infer the communicative intention solely from the agent’s gaze behavior. The results substantiate claims about the pivotal role of gaze in social coordination and relationship formation. Our results further reveal that social expectations are reflected in differential responses to the displayed gaze patterns and may be crucial for impression formation during gaze-based interaction. To the best of our knowledge, this is the first study to document the experience of interactivity in continuous and contingent triadic gaze interactions.

On the strategic value of \u2018shooting yourself in the foot\u2019: an experimental study of burning money

This paper uses a novel experimental design to investigate the strategic value of making a public payoff sacrifice (“burning money”) in a setting modelled after the battle-of-the-sexes game. Unlike prior studies, we find that subjects choose to burn money in a significant portion of decision trials and that burning makes the first movers more likely to achieve their preferred stage two equilibrium outcome. No such effect is observed in a control treatment where money burning is triggered unintentionally. This suggests that payoff sacrifices are important as deliberate signals of one’s further intentions, and can be a source of strategic advantage different from that stemming from being the first party to move. These results are supported by an analysis of subjects’ eye movements, which reveals patterns consistent with forward induction reasoning.

Is clicker training (Clicker + food) better than food-only training for novice companion dogs and their owners?

Clicker training is a training technique whereby a signal (e.g. the ‘click’ of a clicker) is emitted by the trainer immediately after an animal offers a desirable behavior, following which a reward is delivered. Beyond improvements in training time, dog owners report that clicker training can make training more fun and strengthen the relationship between dog and handler. However, it can also be challenging for beginners and make some dogs overly excited or frightened. The aim of this study was to evaluate benefits and disadvantages of clicker training novice pet dogs. Local community members and their dogs (N = 45) volunteered for a 6-week trick training program in a randomized, waitlist-controlled, treatment design with pre- and post-intervention assessments conducted by blinded experimenters. There were three groups: Clicker + food training, Food-only training (without a deliberate signal), and Waitlist Control. Survey-based and behavioral data were collected, measuring the dog-owner relationship, dog impulsivity, and owner-reported training session experiences. Repeated measures mixed effects models were used to evaluate group differences. The Clicker + food and Food-only groups reported improved performance relative to the Control group on tasks included in the training course (F(20, 68) = 2.960, p < 0.001, ηp2 = 0.465). No differences were identified between the two training groups in dog-owner relationship or dog impulsivity measures (all p ≥ 0.102, ηp2 ≤ 0.103). The Clicker + food participants found teaching their dogs to nose-target an object significantly less challenging than the Food-only group (t(28) = 2.511, p = 0.018, d = 0.917), with no differences between groups (p ≥ 0.167, d = 0.499) in any other sessions. This study provides the first evidence that clicker training may make certain tricks less challenging to train, but also that it may not have the disadvantages or benefits previously reported, at least when taught to community-based dog owners in the context of a six-week, beginners, trick training course. Additional intervention-based follow-up studies are recommended to address some of the questions raised by the unexpected findings of the present study.

Retracted Article: Performance benefits of regeneration flexibility and modulation convertibility in elastic optical networks

In planning of the elastic optical networks (EONs), the traditional approach of regeneration node(s) number minimization and the assumption of same modulation format over every segment of lightpath results in the (i) utilization of modulation formats which are less spectrally-efficient, and (ii) unneeded resource(s) loss over shorter route segments which may use modulation formats that are more spectrally-efficient. In this work, we investigate the performance benefits that can be obtained by the introduction of intentional signal regeneration, modulation and spectrum conversion in non-transparent (i.e., translucent) EONs which are based on super-channel transmission. We examine and compare three different cases that may be used to provision the lightpaths which are translucent viz., a basic case of regenerator(s) minimization, and two cases which provision flexible signal regeneration and modulation conversion. For the aforementioned, we develop the routing and spectrum allocation with transceiver and regeneration allocation (RSAwTCRA) problem which, apart from the traditional RSA constraints, also accounts for the (i) regeneration site(s) selection, (ii) modulation format(s) adaptation, and (iii) transceiver(s) assignment to the lightpaths. We develop (i) an integer linear programming method to formulate the RSAwTCRA optimization problem and, (ii) a heuristic (scalable) algorithm to generate the RSAwTCRA solutions. Our simulation results demonstrate that with deliberate signal regeneration and optical carriers’ modulation format(s) adaptation, gains in both, the spectrum and transceiver(s) utilization are achievable for the networks with long distances; however, the savings are negligible for the network with small distances.

Performance benefits of regeneration flexibility and modulation convertibility in elastic optical networks

In planning of the elastic optical networks (EONs), the traditional approach of regeneration node(s) number minimization and the assumption of same modulation format over every segment of lightpath results in the (i) utilization of modulation formats which are less spectrally-efficient, and (ii) unneeded resource(s) loss over shorter route segments which may use modulation formats that are more spectrally-efficient. In this work, we investigate the performance benefits that can be obtained by the introduction of intentional signal regeneration, modulation and spectrum conversion in non-transparent (i.e., translucent) EONs which are based on super-channel transmission. We examine and compare three different cases that may be used to provision the lightpaths which are translucent viz., a basic case of regenerator(s) minimization, and two cases which provision flexible signal regeneration and modulation conversion. For the aforementioned, we develop the routing and spectrum allocation with transceiver and regeneration allocation (RSAwTCRA) problem which, apart from the traditional RSA constraints, also accounts for the (i) regeneration site(s) selection, (ii) modulation format(s) adaptation, and (iii) transceiver(s) assignment to the lightpaths. We develop (i) an integer linear programming method to formulate the RSAwTCRA optimization problem and, (ii) a heuristic (scalable) algorithm to generate the RSAwTCRA solutions. Our simulation results demonstrate that with deliberate signal regeneration and optical carriers’ modulation format(s) adaptation, gains in both, the spectrum and transceiver(s) utilization are achievable for the networks with long distances; however, the savings are negligible for the network with small distances.

Signal restoration in intensity-modulated optical OFDM access systems

It is well known that deliberate signal clipping in an intensity-modulated (IM) laser transmitter helps to overcome the optical orthogonal frequency division multiplexing (OFDM) system performance limitation that is related to the signal high peak-to-average power ratio. The amplitude of a clipped OFDM signal has to be optimized in order to minimize the optical power that is required to achieve a specified system performance. However, the signal clipping introduces nonlinear distortion (so-called clipping noise) and leads to a system performance penalty. In this Letter, the performance of the IM optical OFDM system with digital baseband clipping distortion in the transmitter and clipping noise compensation by means of signal restoration in the digital signal processing unit of the system receiver is analytically evaluated. It is demonstrated that the system bit-error ratio can be reduced by more than an order of magnitude, from 10(-3) to 3.5×10(-5), by applying only the first iteration of the signal restoration algorithm proposed in this Letter. The results of the analytical analysis are verified with brute-force numerical simulations based on direct error counting.

Wireless physical layer security model and resource allocation algorithm in MISO-OFDMA

The problem of wireless security for the downlink of multiuser MISO-OFDMA systems operating over a frequency-selective channel is investigated. Considering interference suppression and resource allocation between different users, a physical-layer security model is proposed that exploits the redundancy of transmit antenna arrays to provide security by deliberate signal randomisation. Signal randomisation causes the receiver's signal to have lower power efficiency than the optimal transmit beamforming. To overcome this problem, a suboptimal, but efficient resource allocation algorithm based on spatial correlation and array redundancy is devised.

A Subcarrier-Reference Scheme for Multiuser MISO-OFDMA Systems with Low Probability of Interception

Recently, Li and Xia proposed a physical-layer security design to guarantee a low probability of interception (LPI) for asynchronous cooperative systems without relying on upper-layer data encryption. The proposed scheme utilizes diagonal unitary codes to perform different encoding in the frequency domain over subcarriers within each OFDM block to randomize the transmitted signals. To build on their idea, in this letter, a subcarrier-reference (SR) transmission scheme is proposed with deliberate signal randomization to achieve LPI in multiuser MISO-OFDMA systems. For each user, one of the allocated subcarriers is chosen by the transmitter to send reference signals, and others are chosen to send the user's information symbols. By some deliberate signal randomization, the eavesdropper cannot detect the transmitted symbols, while the authorized users can operate the system successfully without knowledge of the channels by subcarrier-reference demodulation. Extensive simulations are conducted to demonstrate the scheme's effectiveness.

PERFORMANCE IMPROVEMENT IN SPREAD SPECTRUM IMAGE WATERMARKING USING WAVELETS

This paper investigates the scope of wavelets for performance improvement in spread spectrum image watermarking. Performance of a digital image watermarking algorithm, in general, is determined by the visual invisibility of the hidden data (imperceptibility), reliability in the detection of the hidden information after various common and deliberate signal processing operations (robustness) applied on the watermarked signals and the amount of data to be hidden (payload) without affecting the imperceptibility and robustness properties. In this paper, we propose a few spread spectrum (SS) image watermarking schemes using discrete wavelet transform (DWT), biorthogonal DWT and M-band wavelets coupled with various modulation, multiplexing and signaling techniques. The performance of the watermarking methods are also reported along with the relative merits and demerits.

A distributed differentially encoded OFDM scheme for asynchronous cooperative systems with low probability of interception

Recently, Li, Hwu and Ratazzi have proposed a physical-layer security design to guarantee low probability of interception (LPI) for MIMO systems without relying on upper layer data encryption. The proposed scheme utilizes antenna array redundancy to deliberately randomize the transmitted signals to prevent eavesdropping. Motivated by their idea, in this paper we design a physical-layer transmission scheme to achieve LPI in cooperative systems. There are two major differences in cooperative systems: (1) each relay node may have only one antenna that can not provide antenna array redundancy for signal randomization; (2) there may exist timing errors due to the asynchronous nature of cooperative systems. Considering the two differences, we propose a distributed differentially encoded OFDM transmission scheme with deliberate signal randomization to prevent eavesdropping and exploit the available spatial and frequency diversities in asynchronous cooperative systems. We use diagonal unitary codes to perform the differential encoding in the frequency domain over subcarriers within each OFDM block, or we use general (not necessarily diagonal) unitary codes to perform the differential encoding in the frequency domain across several OFDM blocks. By some deliberate signal randomization, the eavesdropper can not detect the transmitted symbols, while the authorized receiver can perform differential decoding successfully without the knowledge of the channels or the timing errors.

Using Antenna Array Redundancy and Channel Diversity for Secure Wireless Transmissions

The use of signal processing techniques to protect wireless transmissions is proposed as a way to secure wireless networks at the physical layer. This approach addresses a unique weakness of wireless networks whereby network traffic traverses a public wireless medium mak- ing traditional boundary controls ineffective. Specifically, a randomized array transmission scheme is developed to guar- antee wireless transmissions with inherent low-probability- of-interception (LPI). In contrast to conventional spread spectrum or data encryption techniques, this new method exploits the redundancy of transmit antenna arrays for deliberate signal randomization which, when combined with channel diversity, effectively randomizes the eavesdropper's signals but not the authorized receiver's signals. The LPI of this transmission scheme is analyzed via proving the indeterminacy of the eavesdropper's blind deconvolution. Extensive simulations and some preliminary experiments are conducted to demonstrate its effectiveness. The proposed method is useful for securing wireless transmissions, or for supporting upper-layer key management protocols.

On the security of Y-00 under fast correlation and other attacks on the key

The security of the Y-00 direct encryption protocol under correlation attack is addressed. A Y-00 configuration that is more secure than AES under known-plaintext attack is presented. It is shown that under any ciphertext-only attack, full information-theoretic security on the Y-00 seed key is obtained for any encryption box ENC with proper deliberate signal randomization.

Signal modeling for high-performance robust isolated word recognition

This paper describes speech signal modeling techniques which are well-suited to high performance and robust isolated word recognition. We present new techniques for incorporating spectral/temporal information as a function of the temporal position within each word. In particular, spectral/temporal parameters are computed using both variable length blocks with a variable spacing between blocks. We tested features computed with these methods using an alphabet recognition task based on the ISOLET database. The hidden Markov model toolkit (HTK) was used to implement the isolated word recognizer with whole word HMM models. The best accuracy achieved for speaker independent alphabet recognition, using 50 features, was 97.9%, which represents a new benchmark for this task. We also tested these methods with deliberate signal degradation using additive Gaussian noise and telephone band limiting and found that the recognition degrades gracefully and to a smaller degree than for control cases based on MFCC coefficients and delta cepstra terms.

Actos indirectos y en general poco serios: la tradición literaria como pragmática intertextual

The English version of this paper can be found at: http://ssrn.com/abstract=1581424 This paper discusses, as one among a wide range of pragmatic constraints on literature, the intertextual relationship between a work and the tradition it belongs to and which helps define it. It is argued that intertextual signals do not have to be overt even when deliberate, and that deliberate signals do not exhaust a work’s intertextuality (since, for one thing, it will itself give rise to new links). The theory is exemplified with an analysis of two poems by Stephen Crane.

“In Thy Rightful Garb”: Roles and Responsibilities in Scott’s The Abbot

" I N T H Y R I G H T F U L G A R B " : R O L E S A N D R E S P O N S I B I L I T I E S IN S C O T T ' S THE A B B O T JANE MILLGATE University of Toronto T -L he Waverley novels could scarcely be described as difficult works. They are rarely complex in either their plotting or their characterisation, nor do they offer anything especially adventurous in the way of philosophy or analysis. That the experience of reading them is nonetheless far richer than such simplic­ ity and familiarity would suggest can perhaps be attributed to Scott's instinctive feeling for the extension and intensification of meaning attainable through the controlled use of pattern. Underpinning the loose story line of the individual novel is an internal structure of repetition, analogy, variation, and contrast, capable of imposing unity upon seemingly random details of character, setting, and theme. Beyond the individual narrative, and as if framing it, lie patterns of literature, legend, and history, evoked by a whole series of concrete links. In particular, the numerous literary references scattered throughout the Waverley novels - to Shakespeare, Spenser, Milton, Cervantes, and many other writers from the medieval to the modern - are not just outpourings of an overstocked memory but deliberate signals that the world of the particular novel can best, or more fully, be apprehended in terms of the moral and aesthetic shapes embodied in previous literary orderings of human experience. Meaning in the most successful of the Waverley novels emerges not simply from the sequential narrative itself, but also from the perception both of the patterned relationship of separate elements within the novel and of the reverberating associations between this version of pastoral, picaresque, bildungsroman, or romance and those earlier exemplars which the narrative itself has directly or allusively invoked. The Abbot (1820) - one of Scott's finest novels, though one of the least often discussed - provides an especially rich instance of his echoing and re-echoing techniques. The installation of Abbot Ambrosius and his confrontation with the mock Abbot of Unreason sets out in emblematic form some of the book's major oppositions and establishes a pattern which recurs, with significant modifica­ tions, in two other episodes of confusion and disorder: a visit by the hero, Roland Graeme, to the shores of Lochleven during his service as a page to Queen Mary, and the final battle in which the forces of the Queen are defeated. By juxtaposing these three moments, rich as they are in moral and political English Stud ies in Ca n ad a, h i, 2, Summer 1977 196 implications, it is possible to see how Scott works - through scene, character, emblem, and allusion, through the manipulation of framing perspectives, and through the resonating effects of a method of repetition with variation - to bring larger external patterns actively into the reader's mind and to create the tightly organized structure which underlies the apparent simplicity of the novel's linear design. That design embodies the familiar Scott theme of the progress of a child of unknown parentage from an obscure, headstrong, and, in this case, violent adolescent to the kind of young man who can survive in a world of momentous historical events; its working out depends upon Scott's no less familiar use of the standard Romance plot of the lost heir, and his invocation of the traditional Romance ending of a marriage to symbolise the re-establishment of order and the onward movement of life. Although Roland Graeme - "a bastard from the Debateable Land, without either kith, kin, or ally l" 1 - knows neither who he is or who his father was, his impulse is always towards the assertion and achieve­ ment of that rank in life which he feels to be rightly his. But he finds himself continually placed in conditions of dependence or tutelage, treated as a child, kept in the dark, and made a virtual prisoner. Although he eventually re­ nounces his early impulsive violence in favour of more controlled forms of action and becomes increasingly willing to accept the authority...