Short-time Fourier transform laser Doppler holography

We report a demonstration of laser Doppler holography at a sustained acquisition rate of 250 Hz on a 1 Megapixel complementary metal-oxide-semiconductor (CMOS) sensor array and image display at 10 Hz frame rate. The holograms are optically acquired in off-axis configuration, with a frequency-shifted reference beam. Wide-field imaging of optical fluctuations in a 250 Hz frequency band is achieved by turning time-domain samplings to the dual domain via short-time temporal Fourier transformation. The measurement band can be positioned freely within the low radio-frequency spectrum by tuning the frequency of the reference beam in real-time. Video-rate image rendering is achieved by streamline image processing with commodity computer graphics hardware. This experimental scheme is validated by a non-contact vibrometry experiment

Crawford-Sobel meet Lloyd-Max on the grid

The main contribution of this work is twofold. First, we apply, for the first time, a framework borrowed from economics to a problem in the smart grid namely, the design of signaling schemes between a consumer and an electricity aggregator when these have non-aligned objectives. The consumer's objective is to meet its need in terms of power and send a request (a message) to the aggregator which does not correspond, in general, to its actual need. The aggregator, which receives this request, not only wants to satisfy it but also wants to manage the cost induced by the residential electricity distribution network. Second, we establish connections between the exploited framework and the quantization problem. Although the model assumed for the payoff functions for the consumer and aggregator is quite simple, it allows one to extract insights of practical interest from the analysis conducted. This allows us to establish a direct connection with quantization, and more importantly, to open a much more general challenge for source and channel coding.Comment: ICASSP 2014, 5 page

Coordination in State-Dependent Distributed Networks: The Two-Agent Case

This paper addresses a coordination problem between two agents (Agents $1$ and $2$) in the presence of a noisy communication channel which depends on an external system state $\{x_{0,t}\}$. The channel takes as inputs both agents' actions, $\{x_{1,t}\}$ and $\{x_{2,t}\}$ and produces outputs that are observed strictly causally at Agent $2$ but not at Agent $1$. The system state is available either causally or non-causally at Agent $1$ but unknown at Agent $2$. Necessary and sufficient conditions on a joint distribution $\bar{Q}(x_0,x_1,x_2)$ to be implementable asymptotically (i.e, when the number of taken actions grows large) are provided for both causal and non-causal state information at Agent $1$. Since the coordination degree between the agents' actions, $x_{1,t}$ and $x_{2,t}$, and the system state $x_{0,t}$ is measured in terms of an average payoff function, feasible payoffs are fully characterized by implementable joint distributions. In this sense, our results allow us to derive the performance of optimal power control policies on an interference channel and to assess the gain provided by non-causal knowledge of the system state at Agent $1$. The derived proofs readily yield new results also for the problem of state-amplification under a causality constraint at the decoder.Comment: Published in 2015 IEEE International Symposium on Information Theor

Implicit Coordination in Two-Agent Team Problems; Application to Distributed Power Allocation

The central result of this paper is the analysis of an optimization problem which allows one to assess the limiting performance of a team of two agents who coordinate their actions. One agent is fully informed about the past and future realizations of a random state which affects the common payoff of the agents whereas the other agent has no knowledge about the state. The informed agent can exchange his knowledge with the other agent only through his actions. This result is applied to the problem of distributed power allocation in a two-transmitter $M-$band interference channel, $M\geq 1$, in which the transmitters (who are the agents) want to maximize the sum-rate under the single-user decoding assumption at the two receivers; in such a new setting, the random state is given by the global channel state and the sequence of power vectors used by the informed transmitter is a code which conveys information about the channel to the other transmitter.Comment: 6 pages, appears as WNC3 2014: International Workshop on Wireless Networks: Communication, Cooperation and Competition - International Workshop on Resource Allocation, Cooperation and Competition in Wireless Network

Modeling fertility curves in Africa

The modeling of fertility patterns is an essential method researchers use to understand world-wide population patterns. Various types of fertility models have been reported in the literature to capture the patterns specific to developed countries. While much effort has been put into reducing fertility rates in Africa, models which describe the fertility patterns have not been adequately described. This article presents a flexible parametric model that can adequately capture the varying patterns of the age-specific fertility curves of African countries. The model has parameters that are interpretable in terms of demographic indices. The performance of this model was compared with other commonly used models and Akaike’s Information Criterion was used for selecting the model with best fit. The presented model was able to reproduce the empirical fertility data of 11 out of 15 countries better than the other models considered.African countries, age-specific fertility rates, Akaikes Information Criterion, complementary error function, cubic/quadratic spline, polynomial model

Using Resources from a Closely-related Language to Develop ASR for a Very Under-resourced Language: A Case Study for Iban

International audienceThis paper presents our strategies for developing an automatic speech recognition system for Iban, an under-resourced language. We faced several challenges such as no pronunciation dictionary and lack of training material for building acoustic models. To overcome these problems, we proposed approaches which exploit resources from a closely-related language (Malay). We developed a semi-supervised method for building the pronunciation dictionary and applied cross-lingual strategies for improving acoustic models trained with very limited training data. Both approaches displayed very encouraging results, which show that data from a closely-related language, if available, can be exploited to build ASR for a new language. In the final part of the paper, we present a zero-shot ASR using Malay resources that can be used as an alternative method for transcribing Iban speech

Video-rate laser Doppler vibrometry by heterodyne holography

We report a demonstration video-rate heterodyne holography in off-axis configuration. Reconstruction and display of 1 Megapixel holograms is achieved at 24 frames per second, with a graphics processing unit. Our claims are validated with real-time screening of steady-state vibration amplitudes in a wide-field, non-contact vibrometry experiment.Comment: Optics Letters (2011) 00

The Intersection of the Criminal Justice, Education, and Mental Healthcare Systems and Its Influence on Boys and Young Men of Color

The authors provide a scan of the academic and gray literature on the intersection of the criminal justice, mental health, and education systems, and how it influences the lives of at-risk racial/ethnic minority youth (boys and young men of color). As well, the authors identify interventions that aim to improve outcomes for racial/ethnic minority at-risk youth at the intersection of these three structural systems

Quantification en présence de divergence d'intérêts : application aux réseaux d'électricité intelligents

National audienceMotivated by an application to smart grid, this paper generalizes the problem of scalar quantization in the case in which an agent, the consumer, determines the quantization cells and the other agent, the electrical network operator called aggregator, determines the representatives. We know that the standard quantization consists of two fictitious agents, which can be identified as a single one, minimizing the distorsion on the cells and on the representatives. In this paper, we consider a variation of that framework where the payoff functions maximized by the two agents are distincts. Their difference is called bias and implies a new strategic approach to the problem. Using tools from game theory, this work will highlight some key differences between the "strategic quantization" and the standard quantization, namely all communication ressources are not necessarily used, the bias between the payoffs has an influence on the quantity of exchanged information and the speed of convergence of methods analogous to the Llyod-Max algorithm in the strategic caseMotivé par une application issue des « Smart Grid », les « réseaux d'électricité intelligents », cet article généralise le problème de la quantification scalaire dans le cas où un agent, un consommateur, détermine les cellules de quantification et l'autre, un opérateur de réseau appelé agrégateur, les représentants. À la différence de la quantification classique où deux agents, fictifs et que l'on peut supposer ne faire qu'un, minimisent la distorsion sur les cellules et les représentants, les utilités maximisées ici par les deux agents sont distinctes. Leur différence est mesurée par un biais et va conduire à une réinterprétation stratégique du problème de quantification. Reprenant des outils de théorie des jeux, cet article va montrer quelques différences fondamentales entre le cas de la « quantification stratégique » et celui de la quantification classique : toutes les ressources de communication ne sont pas forcément utilisées, le biais entre utilité va fortement conditionner la quantité d'information échangée et la vitesse de convergence des méthodes analogues à l'algorithme de Lloyd-Max dans le cas stratégique

Using closely-related language to build an ASR for a very under-resourced language: Iban

International audienceThis paper describes our work on automatic speech recognition system (ASR) for an under-resourced language, Iban, a language that is mainly spoken in Sarawak, Malaysia. We collected 8 hours of data to begin this study due to no resources for ASR exist. We employed bootstrapping techniques involving a closely-related language for rapidly building and improve an Iban system. First, we used already available data from Malay, a local dominant language in Malaysia, to bootstrap grapheme-to-phoneme system (G2P) for the target language. We also built various types of G2Ps, including a grapheme-based and an English G2P, to produce different versions of dictionaries. We tested all of the dictionaries on the Iban ASR to provide us the best version. Second, we improved the baseline GMM system word error rate (WER) result by utilizing subspace Gaussian mixture models (SGMM). To test, we set two levels of data sparseness on Iban data; 7 hours and 1 hour transcribed speech. We investigated cross-lingual SGMM where the shared parameters were obtained either in monolingual or multilingual fashion and then applied to the target language for training. Experiments on out-of-language data, English and Malay, as source languages result in lower WERs when Iban data is very limited