Miracle-dz/UniFAR-FTUs huggingface dataset:
The Posterior Matching Feedback Scheme for Joint Source-Channel Coding with Bandwidth Expansion

When transmitting a Gaussian source over an AWGN channel with an input power constraint and a quadratic distortion measure, it is well known that optimal performance can be obtained using an analog joint source-channel scalar scheme which merely scales the input and output signals. In the case of bandwidth expansion, such a joint source-channel analog scheme attaining optimal performance is no longer simple. However, when feedback is available a simple and sequential analog linear procedure based on the Schalkwijk-Kailath scheme for communication, is optimal. Recently, we have introduced a fundamental feedback communication scheme,termed \textit{posterior matching}, which generalizes the Schalkwijk-Kailath scheme to arbitrary memoryless channels and input distributions. In this paper, we show how the posterior matching scheme can be adapted to the joint source-channel coding setting with bandwidth expansion and a general distortion measure, when feedback is available.
On Solving General State-Space Sequential Decision Problems using Inference Algorithms

A recently proposed formulation of the stochastic planning and control problem as one of parameter estimation for suitable artificial statistical models has led to the adoption of inference algorithms for this notoriously hard problem. At the algorithmic level, the focus has been on developing Expectation-Maximization (EM) algorithms. For example, Toussaint et al (2006) uses EM with optimal smoothing in the E step to solve finite state-space Markov Decision Processes. In this paper, we extend this EM approach in two directions. First, we derive a non-trivial EM algorithm for linear Gaussian models where the reward function is represented by a mixture of Gaussians, as opposed to the less flexible classical single quadratic function. Second, in order to treat arbitrary continuous state-space models, we present an EM algorithm with particle smoothing. However, by making the crucial observation that the stochastic control problem can be reinterpreted as one of trans-dimensional inference, we are able to propose a novel reversible jump Markov chain Monte Carlo (MCMC) algorithm that is more efficient than its smoothing counterparts. Moreover, this observation also enables us to design an alternative full Bayesian approach for policy search, which can be implemented using a single MCMC run.
The Effect of Low-Level Laser Irradiation on Sperm Motility, and Integrity of the Plasma Membrane and Acrosome in Cryopreserved Bovine Sperm

Background and Objective Freezing changes sperm integrity remarkably. Cryopreservation involves cooling, freezing, and thawing and all these contribute to structural damage in sperm, resulting in reduced fertility potential. Low-level laser irradiation (LLLI) could increase energy supply to the cell and cause reactive oxygen species reduction (ROS), contributing to the restoration of oxygen consumption and adenosine triphosphate synthesis (ATP) in the mitochondria. Our goal was to analyze the effects of low-level laser irradiation on sperm motility and integrity of the plasma membrane and acrosome in cryopreserved bovine sperm. Study Design/Materials and Methods We analyzed 09 samples of bull semen (Bos taurus indicus), divided into three groups: a control group without laser irradiation, a 4J group subjected to a laser irradiation dose of 4 joules, and a 6J group subjected to dose of 6 joules. Samples were divided for the analysis of cell viability and acrosomal membrane integrity using flow cytometry; another portion was used for motion analysis. Irradiation was performed in petri dishes of 30 mm containing 3 ml of semen by an aluminum gallium indium phosphide laser diode with a wavelength of 660 nm, 30 mW power, and energy of 4 and 6 joules for 80 and 120 seconds respectively. Subsequently, the irradiated and control semen samples were subjected to cryopreservation and analyzed by flow cytometry (7AAD and FITC-PSA) using the ISAS - Integrated Semen Analysis System. Results Flow cytometry showed an increase in the percentage of live sperm cells and acrosome integrity in relation to control cells when subjected to irradiation of low-power laser in two different doses of 4 and 6 joules (p < 0.05). In the analysis of straightness, percentage of cell movement, and motility, a dose of 4 joules was more effective (p < 0.05). Conclusion We conclude that LLLI may exert beneficial effects in the preservation of live sperm. A dose of 4 joules prior to cryopreservation was more effective than a dose of 6 joules in preserving sperm motility.
FEM study on the shrinkage property of fiber reinforced mortar

The current paper presents the results of numerical study on the shrinkage property of synthetic fiber reinforced cement mortar, including the discussion about the influence of fiber geometry on the shrinkage performance of mortar matrix. Finite element method (FEM) was used to build the numerical models respectively for the free composite and constrained composite. Cooling method was used to simulate the shrinkage of mortar matrix. Based on the thermal-mechanical coupling analysis, shrinkage and average normal stress of the matrix were obtained. Examples show that increasing fiber volume fraction can take effects both on the decrease of shrinkage and average normal stress of mortar matrix. Although X-type fibers with elastic modulus higher than the matrix can provide better anti-shrinkage property for free mortar, they will increase the average stress in the constrained mortar and thus increase the possibility of original micro-cracks in mortar matrix. X-type fibers with elastic modulus lower than mortar, rather than cylindrical fibers, are suggested for a better achievement in anti-shrinkage and cracking control.
A physical model of the wireless infrared communication channel

A simple analytical model of the wireless infrared communication channel in indoor environments is presented. The infrared signal is modeled as the combination of a diffuse component and a line-of-sight (LOS) or direct component. For the diffuse component alone, the properties of the channel are found using Ulbricht's integrating sphere. When a LOS component is also present, the transfer function depends upon the Rician factor K given by the ratio of the electrical power in the LOS and diffuse signals after the detector. For small K, the transfer function shows notches down to low frequencies, but due to the nature of light never for zero frequency. We confirm that a K-factor /spl ges/13 dB is required also in infrared wireless links in order to support distortionless data transmission beyond 100 Mbit/s. Increasing the directivity at the receiver and/or at the transmitter improves the effective value of K. Here, we show that a moderate directivity will be sufficient for high-speed infrared communication in typical indoor scenarios.
Generating image description by modeling spatial context of an image

Generating the descriptive sentences of a real image is a challenging task in image understanding. The difficulty mainly lies in recognizing the interaction activities between objects, and predicting the relationship between objects and stuff/scene. In this paper, we propose a framework for improving image description generation by addressing the above problems. Our framework mainly includes two models: a unified spatial context model and an image description generation model. The former, as the centerpiece of our framework, models 3D spatial context to learn the human-object interaction activities and predict the semantic relationship between these activities and stuff/scene. The spatial context model casts the problems as latent structured labeling problems, and can be resolved by a unified mathematical optimization. Then based on the semantic relationship, the image description generation model generates image descriptive sentences through the proposed lexicalized tree-based algorithm. Experiments on a joint dataset show that our framework outperforms state-of-the-art methods in spatial co-occurrence context analysis, the human-object interaction recognition, and the image description generation.
Homeostatic Proliferation Fails to Efficiently Reactivate HIV-1 Latently Infected Central Memory CD4+ T Cells

Homeostatic proliferation ensures the longevity of central memory T-cells by inducing cell proliferation in the absence of cellular differentiation or activation. This process is governed mainly by IL-7. Central memory T-cells can also be stimulated via engagement of the T-cell receptor, leading to cell proliferation but also activation and differentiation. Using an in vitro model of HIV-1 latency, we have examined in detail the effects of homeostatic proliferation on latently infected central memory T cells. We have also used antigenic stimulation via anti-CD3/anti-CD28 antibodies and established a comparison with a homeostatic proliferation stimulus, to evaluate potential differences in how either treatment affects the dynamics of latent virus populations. First, we show that homeostatic proliferation, as induced by a combination of IL-2 plus IL-7, leads to partial reactivation of latent HIV-1 but is unable to reduce the size of the reservoir in vitro. Second, latently infected cells are able to homeostatically proliferate in the absence of viral reactivation or cell differentiation. These results indicate that IL-2 plus IL-7 may induce a detrimental effect by favoring the maintenance of the latent HIV-1 reservoir. On the other hand, antigenic stimulation efficiently reactivated latent HIV-1 in cultured central memory cells and led to depletion of the latently infected cells via virus-induced cell death.
THE DISCRETE SPECTRUM OF SELFADJOINT OPERATORS UNDER PERTURBATIONS OF VARIABLE SIGN

Given two selfadjoint operators A and V = V + − V −, we study the motion of the eigenvalues of the operator A(t) = A − tV as t increases. Let α > 0 and let λ be a regular point for A. We consider the quantity N(λ, A, W +, W −, α) defined as the difference between the number of the eigenvalues of A(t) that pass the point λ from right to left and the number of the eigenvalues passing λ from left to right as t increases from 0 to α. We study the asymptotic behavior of N(λ, A, W +, W −, α) as α → ∞. Applications to Schrödinger and Dirac operators are given.
Emergence of scale-free properties in Hebbian networks

The fundamental `plasticity' of the nervous system (i.e high adaptability at different structural levels) is primarily based on Hebbian learning mechanisms that modify the synaptic connections. The modifications rely on neural activity and assign a special dynamic behavior to the neural networks. Another striking feature of the nervous system is that spike based information transmission, which is supposed to be robust against noise, is noisy in itself: the variance of the spiking of the individual neurons is surprisingly large which may deteriorate the adequate functioning of the Hebbian mechanisms. In this paper we focus on networks in which Hebbian-like adaptation is induced only by external random noise and study spike-timing dependent synaptic plasticity. We show that such `HebbNets' are able to develop a broad range of network structures, including scale-free small-world networks. The development of such network structures may provide an explanation of the role of noise and its interplay with Hebbian plasticity. We also argue that this model can be seen as a unification of the famous Watts-Strogatz and preferential attachment models of small-world nets.
Coarse Mesh Partitioning for Tree-Based AMR

In tree-based adaptive mesh refinement, elements are partitioned between processes using a space-filling curve. The curve establishes an ordering between all elements that derive from the same root element, the tree. When representing complex geometries by connecting several trees, the roots of these trees form an unstructured coarse mesh. We present an algorithm to partition the elements of the coarse mesh such that (a) the fine mesh can be load-balanced to equal element counts per process regardless of the element-to-tree map, and (b) each process that holds fine mesh elements has access to the meta data of all relevant trees. As an additional feature, the algorithm partitions the meta data of relevant ghost (halo) trees as well. We develop in detail how each process computes the communication pattern for the partition routine without handshaking and with minimal data movement. We demonstrate the scalability of this approach on up to 917e3 MPI ranks and 371e9 coarse mesh elements, measuring run times of.
Nonlinear Gaussian filter with the colored measurement noise

This paper is concerned with the Gaussian approximation (GA) filtering for a class of nonlinear stochastic systems in the case that the colored measurement noise is modeled as a first-order autoregressive process. First, through the augmentation of the standard measurements, the problem of designing the GA filter with the colored measurement noise is transformed into that of deriving the GA one with the delayed state in the augmented measurement function. Second, through presenting Gaussian approximation about the joint posterior probability density functions (PDF) of the present state, the delayed state and the augmented measurement, the novel GA filter with the delayed state are proposed, which recursively operate by analytical computation and nonlinear Gaussian integrals. The proposed GA filter provides a general and common framework, from which many variations can be developed by utilizing different numerical technologies for computing such nonlinear Gaussian integrals, for example the modified cubature Kalman filter (CKF) in this paper using the spherical-radial cubature rule. The performance of the new method is demonstrated with a simulation example.
On control of inter-session network coding in delay-tolerant mobile social networks

Delay (or disruption) Tolerant Networks (DTNs) are networks made of wireless nodes with intermittent connections. In such networks, various opportunistic routing algorithms have been devised so as to cope with the lack of contemporaneous end-to-end route between a source and a destination. We consider DTNs made of mobile nodes clustered into social communities, with unicast sessions. Network coding is a generalization of routing that has been shown to bring a number of advantages in various communication settings. In particular, inter-session network coding (IS-NC) is known as a difficult optimization problem in general. In this article, we introduce a parameterized pairwise IS-NC control policy for heterogeneous DTNs, that encompasses both routing and coding controls with an energy constraint. We derive its performance modeling thanks to a mean-field approximation leading to a fluid model of the dissemination process, and validate the model with numerical experiments. We discuss the optimization problem of IS-NC control in social DTNs. By showing numerical gains, we illustrate the relevance of our approach that consists in designing IS-NC control policies not reasoning on specific nodes but instead on the coarse-grained underlying community structure of the social network.
Learning and Implementation on the

We address the problem of learning and implementation on the Internet. When agents play repeated games in distributed environments like the Internet, they have very limited a priori information about the other players and the payoo matrix, and the play can be highly asynchronous. Consequently, standard solution concepts like Nash equilibria, or even the serially undominated set, do not apply in such a setting. To construct more appropriate solution concepts, we rst describe the essential properties that constitute \reasonable" learning behavior in distributed environments. We then study the convergence behavior of such algorithms; these results lead us to propose rather non traditional solutions concepts for this context. Finally, we discuss implementation of social choice functions with these solution concepts. We would like to thank Roger Klein and Herv e Moulin for useful discussions and seminar participants at Princeton, Rutgers, Stonybrook and UBC, for helpful comments.
The Arabidopsis TOR Kinase Specifically Regulates the Expression of Nuclear Genes Coding for Plastidic Ribosomal Proteins and the Phosphorylation of the Cytosolic Ribosomal Protein S6

Protein translation is an energy consuming process that has to be fine-tuned at both the cell and organism levels to match the availability of resources. The target of rapamycin kinase (TOR) is a key regulator of a large range of biological processes in response to environmental cues. In this study, we have investigated the effects of TOR inactivation on the expression and regulation of Arabidopsis ribosomal proteins at different levels of analysis, namely from transcriptomic to phosphoproteomic. TOR inactivation resulted in a coordinated down-regulation of the transcription and translation of nuclear-encoded mRNAs coding for plastidic ribosomal proteins, which could explain the chlorotic phenotype of the TOR silenced plants. We have identified in the 5′ untranslated regions (UTRs) of this set of genes a conserved sequence related to the 5′ terminal oligopyrimidine motif, which is known to confer translational regulation by the TOR kinase in other eukaryotes. Furthermore, the phosphoproteomic analysis of the ribosomal fraction following TOR inactivation revealed a lower phosphorylation of the conserved Ser240 residue in the C-terminal region of the 40S ribosomal protein S6 (RPS6). These results were confirmed by Western blot analysis using an antibody that specifically recognizes phosphorylated Ser240 in RPS6. Finally, this antibody was used to follow TOR activity in plants. Our results thus uncover a multi-level regulation of plant ribosomal genes and proteins by the TOR kinase.
A polynomial linear search algorithm for the n-dimensional knapsack problem

We present a Linear Search Algorithm which decides the n-dimensional knapsack problem in n4log(n) + 0. (n3) steps. This algorithm works for inputs consisting of n numbers for some arbitrary but fixed integer n. This result solves an open problem posed for example in [6] and [7] by Dobkin / Lipton and A.C. C. Yao, resp. It destroys the hope of proving large lower bounds for this NP-complete problem in the model of Linear Search Algorithms.
Inference Rules and their Application to Recognizing Textual Entailment

In this paper, we explore ways of improving an inference rule collection and its application to the task of recognizing textual entailment. For this purpose, we start with an automatically acquired collection and we propose methods to refine it and obtain more rules using a hand-crafted lexical resource. Following this, we derive a dependency-based structure representation from texts, which aims to provide a proper base for the inference rule application. The evaluation of our approach on the recognizing textual entailment data shows promising results on precision and the error analysis suggests possible improvements.
Lyman-α Imaging of a Very Luminous z = 2 . 3 Starburst Galaxy with WFPC 2 ⋆

We investigate the Lyα and UV continuum morphology of one of the most luminous known Lyman α emitting galaxies (the ‘Coup Fourré Galaxy’), associated with a z = 2.3 damped Lyα absorption system in the spectrum of the QSO PHL 957 (Lowenthal et al. 1991). The galaxy is observed with the HST WFPC2, through a narrow filter (F410M) corresponding to rest-frame Lyα for a total exposure time of 41.2 ksec, plus shorter exposures in F555W and F814W. In all three passbands, the galaxy is resolved into a close (∼ 0.35 arcsec) pair of two components, CFgA and CFgB, both of which are extended and elongated. The profile of CFgA is consistent with an exponential disk of similar scale-length in Lyα (rexp = 0.23 arcsec) and continuum (rexp = 0.20 arcsec), and no evidence of a central point source. In contrast, CFgB is closer to a bulge profile. We find that CFgA has by far the higher ratio of Lyα to continuum flux, and from the observed colours estimate rest-frame equivalent widths of W (Lyα) = 151 ± 16Å for CFgA and 33 ± 13Å for CFgB. From the F814W and F555W magnitudes we estimate rest-frame blue-band absolute magnitudes (for H0 = 50 km s Mpc and q0 = 0.05) of -23.12 for CFgA and -23.24 for CFgB, significantly brighter than local galaxies of the same size. CFgA shows a remarkable 3.9 magnitudes of surface brightness enhancement relative to local spirals. This object appears to be at the upper limit of both the range of surface brightness evolution observed in z > 2 galaxies and the range of W (Lyα) in any starforming galaxy. We speculate that its extreme surface brightness results from a very luminous starburst (∼ 200M⊙yr ), triggered by the merger of the two components, and the high W (Lyα) from a brief phase of the starburst in which most Lyα photons can escape, as predicted in the models of Tenorio-Tagle et al. (1999). We also investigate the F410M image of the QSO PHL 957. Subtraction of a normalized point-spead function leaves no significant residuals – the QSO is consistent with a pure point source and we do not detect either the host galaxy or the damped Lyα absorbing galaxy. We search for other galaxies with strong Lyα emission at z ∼ 2.3–2.4, selecting these by a colour (m410 − V555)AB < −0.2. Eight candidate Lyα sources, all fainter than the Coup Fourré galaxy, are identified in our field. One is a point-source and may be an AGN; the others are of similar size to the Coup Fourré Galaxy but lower surface brightness, knotty and asymmetric. They appear typical of Lyman break galaxies but with colours indicating W (Lyα) ∼ 100Å.
“Is It Too Much to Ask That We’re Allowed to Win the Game?”: Character Attachment and Agency in the Mass Effect 3 Ending Controversy

The interaction between the concepts of character attachment, agency, and choice in a video game narrative was investigated using BioWare’s Mass Effect trilogy. Posts on a BioWare forum discussing the depiction of their player characters in the ending sequences of Mass Effect 3, the final game in the trilogy, were downloaded and analyzed using thematic analysis. Players demonstrated emotional attachment for the characters and narrative and expected to see the consequences of their choices play out, as in the previous games. Furthermore, players conflated winning the game with achieving a narratively satisfactory ending for the game world and its characters indicating emotional consequences for players that developers should consider when designing games with a high degree of player choice and agency. However, for some players character attachment is incongruous as they described Shepard as “acting out of character,” which needs further research.