Miracle-dz/UniFAR-FTUs huggingface dataset:
The impact of agent size and number of rounds on cooperation in the iterated Prisoner's Dilemma

The chance that a population of iterated Prisoner's Dilemma playing agents will evolve to a cooperative state is strongly influenced by the duration of the encounter. With only one round of Prisoner's Dilemma, the populations rapidly evolve to the always-defect Nash equilibrium. Durations exceeding the number of rounds to which the agent representation could conceivably count are most likely to yield cooperation but require more computer resources. Reported here is a careful study of different encounter lengths and their impact on cooperation using finite state machines, which are known to yield high levels of cooperation for long encounter durations. Agents with different numbers of states are used. This research, in addition to highlighting one of the boundaries of the evolution of cooperation for evolving agents, serves as a parameter setting study for future research that permits a reduction in the computational resources required. A recently developed tool known as a play profile is used to determine the distribution of agent behaviour by sorting the final fitness scores achieved in each important epoch of evolution. It was found that only 41 to 64 rounds are required to achieve the same level of cooperation as that achieved in 150 rounds, with conservative estimates lying between 60 and 85 rounds. Even the conservative estimates include approximately half as many rounds of play as the current standard.
The Pathway Editor: A tool for managing complex biological networks

Biological networks are systems of biochemical processes inside a cell that involve cellular constituents such as DNA, RNA, proteins, and various small molecules. Pathway maps are often used to represent the structure of such networks with associated biological information. Several pathway editors exist, and they vary according to specific domains of knowledge. This paper presents a review of existing pathway editors, along with an introduction to the Edinburgh Pathway Editor (EPE). EPE was designed for the annotation, visualization, and presentation of a wide variety of biological networks that include metabolic, genetic, and signal transduction pathways. EPE is based on a metadata-driven architecture. The editor supports the presentation and annotation of maps, in addition to the storage and retrieval of reaction kinetics information in relational databases that are either local or remote. EPE also has facilities for linking graphical objects to external databases and Web resources, and is capable of reproducing most existing graphical notations and visual representations of pathway maps. In summary, EPE provides a highly flexible tool for combining visualization, editing, and database manipulation of information relating to biological networks. EPE is open-source software, distributed under the Eclipse open-source application platform license.
On the linkage between AMPA and NMDA receptor-mediated EPSPs in homosynaptic long-term depression in the hippocampal CA1 region of young rats

Homosynaptic long-term depression (LTD) was studied in hippocampal slices from 12–18-d-old rats using field EPSP recording in the apical dendritic layer of CA1 pyramidal cells. Independent estimates of the alpha-amino-3-hydroxy-5-methylisoxazolepropionic acid (AMPA) and the N- methyl-D-aspartic acid (NMDA) receptor-mediated components of the field EPSP were obtained in parallel using early and late measurements of a dual-component EPSP in a low-magnesium solution. LTD was induced by low- frequency stimulation (LFS; 2 Hz for 10 min), resulting in equal relative changes of the AMPA and NMDA receptor-mediated components. Under conditions when the AMPA receptor-mediated component was fully blocked, a similarly sized LTD was observed for the pure NMDA receptor- mediated EPSP (measured as initial slope or peak amplitude). Equal changes in AMPA and NMDA receptor-mediated components occurred also upon application of the adenosine agonist N6-cyclohexyladenosine (CHA), known to act by decreasing transmitter release. On the other hand, LTD was found to interact in a multiplicative manner with the presynaptic release changes induced by CHA and by paired-pulse facilitation. The induction of the LTDs of both AMPA and NMDA receptor-mediated EPSPs was blocked by the NMDA receptor antagonist D(-)-2-amino-5- phosphonopentanoic acid and by the phosphatase inhibitor okadaic acid. Partial blockade of LTD by okadaic acid resulted in equal partial blockade of the LTDs of the AMPA and NMDA receptor-mediated components. On the other hand, the L-type calcium channel blocker nifedipine, the metabotropic glutamate receptor antagonist (RS)-alpha-methyl-4- carboxyphenylglycine, the nitric oxide synthase inhibitor N omega-nitro- L-arginine, and the heme oxygenase inhibitor protoporphyrin IX zinc(II) had no effect on LTD of either the AMPA or the NMDA receptor-mediated component. These results of equal changes of AMPA and NMDA receptor- mediated components of the field EPSP in association with LTD, and the consistent parallelism of effects or noneffects on these components by various receptor antagonists and enzyme inhibitors, seem more easily explained by a presynaptic locus for LTD than by a postsynaptic one.
Is Your Web Server Suffering from Undue Stress due to Duplicate Requests?

An important, if not very well known, problem that afflicts many web servers is duplicate client browser requests due to server-side problems. A legitimate request is followed by a redundant request, thus increasing the load on the server and corrupting state at the server end (such as, the hit count for the page) and at the client end (such as, state maintained through a cookie). This problem has been reported in many developer blogs and has been found to afflict even popular web sites, such as CNN and YouTube. However, to date, there has not been a scientific, technical solution to this problem that is browser vendor neutral. In this paper, we provide such a solution which we call GRIFFIN. We identify that the two root causes of the problem are missing resource at the server end or duplicated Javascripts embedded in the page. We have the insight that dynamic tracing of the function call sequence creates a signature that can be used to differentiate between legitimate and duplicate requests. We apply our technique to find unreported problems in a large production scientific collaboration web service called HUBzero, which arefixed upon reporting the problems. Our experiments show an average overhead of 1.29X for tracing the PHP-runtime on HUBzero across 60 unique HTTP transactions. GRIFFIN has zero false-positives (when run across HTTP transaction of size one and two) and an average detection accuracy of 78% across 60 HTTP transactions.
The missing metal problem — I. How many metals are in submillimetre galaxies?

At redshifts larger than 2, a large fraction (80 per cent) of the metals is apparently as yet undetected. We use a sample of submillimetre-selected galaxies (SMGs) with molecular gas and dynamical mass measurements from the literature in order to put constraints on the contribution of such galaxies to the total metal budget. Compared with Lyman break galaxies (LBGs), for example, SMGs are rarer (by a factor of 10 or more), but contain much more gas and are more metal-rich. We estimate that SMGs brighter than 3 mJy contain only ≲9 per cent of the metals, when we combine the observed dynamical masses (〈Mdyn〉∼ few × 1011 M⊙), number density (n≃ 10−4 Mpc−3), observed gas metallicity (Z≃ 1–2 Z⊙), and observed gas fractions (fgas≈ 40 per cent), assuming a molecular to neutral hydrogen ratio of 1. Including SMGs fainter than 3 mJy, we estimate that SMGs contain about ≤15 per cent of the metals, where our incompleteness correction is estimated from the dust mass function. Our results are strong upper limits, given that high gas fractions and high overall metallicity are mutually exclusive. In summary, SMGs make a significant contribution to the metal budget (≲15 per cent) but not sufficient to solve the ‘missing metal problem’. A consequence of our results is that SMGs can only add ≈3.5 per cent to ΩDLA, and cannot be the source of a significant population of dusty DLAs.
Multi-Behavioral Sequential Prediction with Recurrent Log-Bilinear Model

With the rapid growth of Internet applications, sequential prediction in collaborative filtering has become an emerging and crucial task. Given the behavioral history of a specific user, predicting his or her next choice plays a key role in improving various online services. Meanwhile, there are more and more scenarios with multiple types of behaviors, while existing works mainly study sequences with a single type of behavior. As a widely used approach, Markov chain based models are based on a strong independence assumption. As two classical neural network methods for modeling sequences, recurrent neural networks cannot well model short-term contexts, and the log-bilinear model is not suitable for long-term contexts. In this paper, we propose a Recurrent Log-BiLinear (RLBL) model. It can model multiple types of behaviors in historical sequences with behavior-specific transition matrices. RLBL applies a recurrent structure for modeling long-term contexts. It models several items in each hidden layer and employs position-specific transition matrices for modeling short-term contexts. Moreover, considering continuous time difference in behavioral history is a key factor for dynamic prediction, we further extend RLBL and replace position-specific transition matrices with time-specific transition matrices, and accordingly propose a Time-Aware Recurrent Log-BiLinear (TA-RLBL) model. Experimental results show that the proposed RLBL model and TA-RLBL model yield significant improvements over the competitive compared methods on three datasets, i.e., Movielens-1M dataset, Global Terrorism Database and Tmall dataset with different numbers of behavior types.
Superpixel-Based Classification Using K Distribution and Spatial Context for Polarimetric SAR Images

Classification techniques play an important role in the analysis of polarimetric synthetic aperture radar (PolSAR) images. PolSAR image classification is widely used in the fields of information extraction and scene interpretation or is performed as a preprocessing step for further applications. However, inherent speckle noise of PolSAR images hinders its application on further classification. A novel supervised superpixel-based classification method is proposed in this study to suppress the influence of speckle noise on PolSAR images for the purpose of obtaining accurate and consistent classification results. This method combines statistical information with spatial context information based on the stochastic expectation maximization (SEM) algorithm. First, a modified simple linear iterative clustering (SLIC) algorithm is utilized to generate superpixels as classification elements. Second, class posterior probabilities of superpixels are calculated by a K distribution in iterations of SEM. Then, a neighborhood function is defined to express the spatial relationship among adjacent superpixels quantitatively, and the class posterior probabilities are updated by this predefined neighborhood function in a probabilistic label relaxation (PLR) procedure. The final classification result is obtained by the maximum a posteriori decision rule. A simulated image, a spaceborne RADARSAT-2 image, and an airborne AIRSAR image are used to evaluate the proposed method, and the classification accuracy of our proposed method is 99.28%, 93.16% and 89.70%, respectively. The experimental results indicate that the proposed method obtains more accurate and consistent results than other methods.
Nonlinear Spatial Integration in the Receptive Field Surround of Retinal Ganglion Cells

Throughout different sensory systems, individual neurons integrate incoming signals over their receptive fields. The characteristics of this signal integration are crucial determinants for the neurons' functions. For ganglion cells in the vertebrate retina, receptive fields are characterized by the well-known center-surround structure and, although several studies have addressed spatial integration in the receptive field center, little is known about how visual signals are integrated in the surround. Therefore, we set out here to characterize signal integration and to identify relevant nonlinearities in the receptive field surround of ganglion cells in the isolated salamander retina by recording spiking activity with extracellular electrodes under visual stimulation of the center and surround. To quantify nonlinearities of spatial integration independently of subsequent nonlinearities of spike generation, we applied the technique of iso-response measurements as follows: using closed-loop experiments, we searched for different stimulus patterns in the surround that all reduced the center-evoked spiking activity by the same amount. The identified iso-response stimuli revealed strongly nonlinear spatial integration in the receptive field surrounds of all recorded cells. Furthermore, cell types that had been shown previously to have different nonlinearities in receptive field centers showed similar surround nonlinearities but differed systematically in the adaptive characteristics of the surround. Finally, we found that there is an optimal spatial scale of surround suppression; suppression was most effective when surround stimulation was organized into subregions of several hundred micrometers in diameter, indicating that the surround is composed of subunits that have strong center-surround organization themselves.
Tracking and beamforming for multiple simultaneous speakers with probabilistic data association filters

In prior work, we developed a speaker tracking system based on an extended Kalman filter using time delays of arrival (TDOAs) as acoustic features. While this system functioned well, its utility was limited to scenarios in which a single speaker was to be tracked. In this work, we remove this restriction by generalizing the IEKF, first to a probabilistic data association filter, which incorporates a clutter model for rejection of spurious acoustic events, and then to a joint probabilistic data association filter (JPDAF), which maintains a separate state vector for each active speaker. In a set of experiments conducted on seminar and meeting data, the JPDAF speaker tracking system reduced the multiple object tracking errror from 20.7% to 14.3% with respect to the IEKF system. In a set of automatic speech recognition experiments conducted on the output of a 64 channel microphone array which was beamformed using automatic speaker position estimates, applying the JPDAF tracking system reduced word error rate from 67.3% to 66.0%. Moreover, the word error rate on the beamformed output was 13.0% absolute lower than on a single channel of the array. Index Terms: acoustic source localization, Kalman filter, person tracking, far-field speech recognition, microphone arrays
A general framework for development of the cortex-like visual object recognition system: Waves of spikes, predictive coding and universal dictionary of features

This study is focused on the development of the cortex-like visual object recognition system. We propose a general framework, which consists of three hierarchical levels (modules). These modules functionally correspond to the V1, V4 and IT areas. Both bottom-up and top-down connections between the hierarchical levels V4 and IT are employed. The higher the degree of matching between the input and the preferred stimulus, the shorter the response time of the neuron. Therefore information about a single stimulus is distributed in time and is transmitted by the waves of spikes. The reciprocal connections and waves of spikes implement predictive coding: an initial hypothesis is generated on the basis of information delivered by the first wave of spikes and is tested with the information carried by the consecutive waves. The development is considered as extraction and accumulation of features in V4 and objects in IT. Once stored a feature can be disposed, if rarely activated. This causes update of feature repository. Consequently, objects in IT are also updated. This illustrates the growing process and dynamical change of topological structures of V4, IT and connections between these areas.
Relation between magnetic fields and electric currents in plasmas

Abstract. Maxwell's equations allow the magnetic field B to be calculated if the electric current density J is assumed to be completely known as a function of space and time. The charged particles that constitute the current, however, are subject to Newton's laws as well, and J can be changed by forces acting on charged particles. Particularly in plasmas, where the concentration of charged particles is high, the effect of the electromagnetic field calculated from a given J on J itself cannot be ignored. Whereas in ordinary laboratory physics one is accustomed to take J as primary and B as derived from J , it is often asserted that in plasmas B should be viewed as primary and J as derived from B simply as ( c /4π)∇× B . Here I investigate the relation between ∇× B and J in the same terms and by the same method as previously applied to the MHD relation between the electric field and the plasma bulk flow vmv2001: assume that one but not the other is present initially, and calculate what happens. The result is that, for configurations with spatial scales much larger than the electron inertial length λ e , a given ∇× B produces the corresponding J , while a given J does not produce any ∇× B but disappears instead. The reason for this can be understood by noting that ∇× B ≠4π/ c ) J implies a time-varying electric field (displacement current) which acts to change both terms (in order to bring them toward equality); the changes in the two terms, however, proceed on different time scales, light travel time for B and electron plasma period for J , and clearly the term changing much more slowly is the one that survives. (By definition, the two time scales are equal at λ e .) On larger scales, the evolution of B (and hence also of ∇× B ) is governed by ∇× E , with E determined by plasma dynamics via the generalized Ohm's law; as illustrative simple examples, I discuss the formation of magnetic drift currents in the magnetosphere and of Pedersen and Hall currents in the ionosphere. Keywords. Ionosphere (Electric fields and currents) – Magnetospheric physics (Magnetosphere-ionosphere interactions) – Space plasma physics (Kinetic and MHD theory)
A proximal algorithm for joint resource allocation and minimizing carbon footprint in geo-distributed fog computing

Large-scale Internet applications, such as content distribution networks, are deployed in a geographically distributed manner and emit massive amounts of carbon footprint at the data center. To provide uniform low access latencies, Cisco has introduced Fog computing as a new paradigm which can transform the network edge into a distributed computing infrastructure for applications. Fog nodes are geographically distributed and the deployment size at each location reflects the regional demand for the application. Thus, we need to control the fraction of user traffic to data center to maximize the social welfare. In this paper, we consider the emerging problem of joint resource allocation and minimizing carbon footprint problem for video streaming service in Fog computing. To solve the largescale optimization, we develop a distributed algorithm based on the proximal algorithm and alternating direction method of multipliers (ADMM). The numerical results show that our algorithm converges to near optimum within fifteen iterations, and is insensitive to step sizes.
As‐Rigid‐AsPossible Distance Field Metamorphosis

Widely used for morphing between objects with arbitrary topology, distance field interpolation (DFI) handles topological transition naturally without the need for correspondence or remeshing, unlike surface‐based interpolation approaches. However, lack of correspondence in DFI also leads to ineffective control over the morphing process. In particular, unless the user specifies a dense set of landmarks, it is not even possible to measure the distortion of intermediate shapes during interpolation, let alone control it. To remedy such issues, we introduce an approach for establishing correspondence between the interior of two arbitrary objects, formulated as an optimal mass transport problem with a sparse set of landmarks. This correspondence enables us to compute non‐rigid warping functions that better align the source and target objects as well as to incorporate local rigidity constraints to perform as‐rigid‐aspossible DFI. We demonstrate how our approach helps achieve flexible morphing results with a small number of landmarks.
FuGeNeSys-a fuzzy genetic neural system for fuzzy modeling

The author has developed a novel approach to fuzzy modeling from input-output data. Using the basic techniques of soft computing, the method allows supervised approximation of multi-input multi-output (MIMO) systems. Typically, a small number of rules are produced. The learning capacity of FuGeNeSys is considerable, as is shown by the numerous applications developed. The paper gives a significant example of how the fuzzy models developed are generally better than those to be found in literature as concerns simplicity and both approximation and classification capabilities.