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

Emergency purchasing situations: implications for consumer decision-making

This article introduces the Emergency Purchasing Situation (EPS) as a distinct buying context. EPSs stem from an unexpected event (unanticipated need or timing of a need), as well as high product importance, which are associated with a short time frame for consumer decision-making. Our conceptual review integrates largely disconnected strands of research and theories relevant to EPSs and offers a series of independent propositions to understand how these situations might affect consumer decision-making, specifically heuristic versus reflective information processing in product evaluation. We discuss changes induced by the buying context in terms of regulatory focus, perceived time pressure, and stress. Our propositions further account for purchase involvement in the form of product importance, purchase risk, and product substitutability. Finally, we consider how individual differences (expertise and trust) may affect evaluation processes. Our discussion reflects on the implications of our model, avenues for future research, and how an understanding of EPSs can be used to improve managerial practice

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

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

MK-GGBS foams: Relation between mechanical parameters and morphological parameters

This study aims to link the thermomechanical properties of blended metakaolin-ground granulated blast furnace slag (MK-GGBS) foam concrete (FC) to their morphological parameters. The AAM FC matrix is composed of MK, GGBS and an alkaline solution. The binder is composed of 62.5% of MK, 12.5% of GGBS and 25% of dry extract of alkaline solution. Water came from the alkaline solution and additional water to reach a water/binder ratio of 0.36. The AAM paste was aerated with different H2O2 contents (1, 1.5 and 2%) and stabilized with surfactant. The surfactant content ranged from 0.002 to 0.05 %. Lightweight AAMs were obtained with density from 264 to 480 kg/m3. The analysis of the sectional view pictures revealed that AAMs FC porous structure is highly influenced by both H2O2 and surfactant contents. The H2O2 content modify the FC density while the surfactant content mostly modified the bubble distribution at a constant density. Please click Additional Files below to see the full abstract

Assessment of the diagnostic accuracy of nerve conduction study and the correlation between severity of symptoms and nerve conduction studies in carpal tunnel syndrome

Background: This study was done to assess the diagnostic accuracy of nerve conduction study in carpal tunnel syndrome and comparability of nerve conduction measures before and after carpal tunnel release.Methods: 31 patients (30 females and 1 male) with carpal tunnel syndrome were subjected to nerve conduction study and Boston symptom severity scores before surgery and at 3 months post-operative period and nerve conduction values compared. The effect of duration of symptoms on nerve conduction values was studied.Results: Nerve conduction studies were found to be reliable in diagnosing carpal tunnel syndrome. 61.30% patients showed a right-handed involvement, or right side getting affected first in a bilateral case. 60-80% patients had Boston symptom severity scores which were comparable to the nerve conduction grades ascertaining the relationship between them. Only 58.8% patients with extreme and severe NCS grades preoperatively showed improvement post-surgical release. In patients with symptoms for more than 12 months, only 33.33% had improved nerve conduction grades post-surgical release at 3 months, validating the need for early surgical release.Conclusions: Nerve conduction study was found to be a reliable diagnostic modality for diagnosis of carpal tunnel syndrome and nerve conduction study values correlated with the Boston symptom severity score. The post-operative nerve conduction values revealed definite neurological improvement in patients who underwent early surgical management. Hence, we recommend early release for carpal tunnel syndrome patients for speedy recovery from the condition