Miracle-dz/UniFAR-FTUs huggingface dataset:
On Characterization of Elementary Trapping Sets of Variable-Regular LDPC Codes

In this paper, we study the graphical structure of elementary trapping sets (ETSs) of variable-regular low-density parity-check (LDPC) codes. ETSs are known to be the main cause of error floor in LDPC coding schemes. For the set of LDPC codes with a given variable node degree dl and girth g, we identify all the nonisomorphic structures of an arbitrary class of (a, b) ETSs, where a is the number of variable nodes and b is the number of odd-degree check nodes in the induced subgraph of the ETS. This paper leads to a simple characterization of dominant classes of ETSs (those with relatively small values of a and b) based on short cycles in the Tanner graph of the code. For such classes of ETSs, we prove that any set S in the class is a layered superset (LSS) of a short cycle, where the term layered is used to indicate that there is a nested sequence of ETSs that starts from the cycle and grows, one variable node at a time, to generate S. This characterization corresponds to a simple search algorithm that starts from the short cycles of the graph and finds all the ETSs with LSS property in a guaranteed fashion. Specific results on the structure of ETSs are presented for dl = 3, 4, 5, 6, g = 6, 8, and a, b ≤ 10 in this paper. The results of this paper can be used for the error floor analysis and for the design of LDPC codes with low error floors.
Dense multiple antenna systems

We consider multiple antenna systems in which a large number of antennas occupy a given physical volume. In this regime the assumptions of the standard models of multiple antennas systems become questionable. We show that for such spatially dense multiple antenna systems one should expect the behavior of the capacity to be qualitatively different than what the standard multiple antenna models predict.
Properties of Derivative Expansion Approximations to the Renormalization Group

Approximation only by derivative (or more generally momentum) expansions, combined with reparametrization invariance, turns the continuous renormalization group into a set of partial differential equations which at fixed points become nonlinear eigenvalue equations for the anomalous scaling dimension η. We review how these equations provide a powerful and robust means of discovering and approximating non-perturbative continuum limits. Gauge fields are briefly discussed. Particular emphasis is placed on the role of reparametrization invariance, and the convergence of the derivative expansion is addressed.
Regular Expression Matching and Operational Semantics

Many programming languages and tools, ranging from grep to the Java String library, contain regular expression matchers. Rather than first translating a regular expression into a deterministic finite automaton, such implementations typically match the regular expression on the fly. Thus they can be seen as virtual machines interpreting the regular expression much as if it were a program with some non-deterministic constructs such as the Kleene star. We formalize this implementation technique for regular expression matching using operational semantics. Specifically, we derive a series of abstract machines, moving from the abstract definition of matching to increasingly realistic machines. First a continuation is added to the operational semantics to describe what remains to be matched after the current expression. Next, we represent the expression as a data structure using pointers, which enables redundant searches to be eliminated via testing for pointer equality. From there, we arrive both at Thompson's lockstep construction and a machine that performs some operations in parallel, suitable for implementation on a large number of cores, such as a GPU. We formalize the parallel machine using process algebra and report some preliminary experiments with an implementation on a graphics processor using CUDA.
A COMPARISON OF THE CHANGES IN FINE STRUCTURE OF L CELLS DURING SINGLE CYCLES OF VIRAL MULTIPLICATION, FOLLOWING THEIR INFECTION WITH THE VIRUSES OF MENGO AND ENCEPHALOMYOCARDITIS

The virus of encephalomyocarditis (EMC), examined by the negative-contrast method, is indistinguishable from the serologically related Mengovirus. The particles are 270 to 280 A in diameter. The surface of EMC is composed of an undetermined number of subunits. Frequent sampling of infected cells was carried out throughout one-step cycles of viral multiplication to observe cytopathic changes occurring in L cells infected by these two related RNA viruses. EMC and Mengovirus, which multiply at equal rates, in most respects elicit similar alterations in cell fine structure. Rearrangement and changes in nuclear material accompanied by formation of small vesicles in the centrosphere region commence at 4 to 6 hours after infection. Thereafter a progressive degeneration of the nucleus and vesiculation of the cytoplasm are observed up to 18 to 20 hours. Increased numbers of small dense granules, indistinguishable from ribonucleoprotein particles, appear in the cytoplasm between 8 and 14 hours after infection. L cells infected with Mengovirus become permeable to Erythrocin more slowly than those infected with EMC. Only in the case of Mengovirus infection are large aggregates of dense material first observed in the cytoplasm at 8 hours, followed by the appearance of crystals probably composed of Mengovirus particles, at 12 hours. Differences in the rates of cell permeability after infection with EMC and Mengovirus are discussed in relation to formation of virus crystals and plaque-type mutants.
UPGMA Mouse Bovine Lemur Tarsier Squir Monk Jpn Macaq Rhesus Mac Crab − E . Mac BarbMacaq Gibbon Orang Gorilla Chimp Human NJ Mouse Bovine Lemur

These notes should enable the user to estimate phylogenetic trees from alignment data with different methods using the phangorn package [12]. Several functions of phangorn are also described in more detail in [8]. For more theoretical background on all the methods see e.g. [3, 15]. This document illustrates some of the phangorn features to estimate phylogenetic trees using different reconstruction methods. Small adaptations to the scripts in section 6 should enable the user to perform phylogenetic analyses.
Identification of the Preprotein Binding Domain of SecA*

SecA, the preprotein translocase ATPase, has a helicase DEAD motor. To catalyze protein translocation, SecA possesses two additional flexible domains absent from other helicases. Here we demonstrate that one of these “specificity domains” is a preprotein binding domain (PBD). PBD is essential for viability and protein translocation. PBD mutations do not abrogate the basal enzymatic properties of SecA (nucleotide binding and hydrolysis), nor do they prevent SecA binding to the SecYEG protein conducting channel. However, SecA PBD mutants fail to load preproteins onto SecYEG, and their translocation ATPase activity does not become stimulated by preproteins. Bulb and Stem, the two sterically proximal PBD substructures, are physically separable and have distinct roles. Stem binds signal peptides, whereas the Bulb binds mature preprotein regions as short as 25 amino acids. Binding of signal or mature region peptides or full-length preproteins causes distinct conformational changes to PBD and to the DEAD motor. We propose that (a) PBD is a preprotein receptor and a physical bridge connecting bound preproteins to the DEAD motor, and (b) preproteins control the ATPase cycle via PBD.
Ancient states and ordinary people: A feminist re-imagining of ancient Maya power and the everyday

Maya archaeology continues to be defined by a schism between ‘politic/s and state’ and ‘everyday life and ordinary people. ’ Using feminist theory, this paper deconstructs this dichotomy by considering the intellectual history and theoretical perspectives that continue to reify these boundaries and its connections to modern neoliberal discourses. How we conceive of the state – of what it is, and how it interacts with the rest of society – is at the heart of neo-evolutionary models of state formation; these impact our understanding of how ancient Maya society operated and the ways in which power, politics and class function. Archaeological fascination with elites and rulers, both in scholarly and public circles, creates a narrative focused on individual achievement, and a quest for wealth and material access; values lauded by the neoliberal state. Alternative readings of complexity illustrate that everyday life of ordinary people is nuanced, intentional, and inherently political. Such work forces us to reconsider this dichotomy and recognize it as a dialectical and mutually constitutive process.
Data caching in data integration systems based on AXML technology

AXML (active XML) is a framework for peer-to-peer data integration from XML sources. In AXML documents data can be presented extensionally or intentionally by including calls to local or remote Web services. In complex AXML-based systems data retrieval can be inefficient. In the paper we propose a caching mechanism for systems based on active XML. We show how it can influence network communication and data integration processes.
Perception and interpretation of high-pass filtered images

Digital high-pass filtering is used frequently to enhance details in scientific, industrial, and military images. High-pass filtered (HPF) images also are used both to illustrate and test models of visual perception. The visual system appears to interpret HPF images in the context of a multiplicative model of high-frequency reflectance and low-frequency illumination whenever possible. HPF images can be treated as a form of two-dimensional amplitude modulation signals. The low-frequency information, which is coded in the modulation envelope, disappears with the carrier if low-pass filtered. The envelope may be retrieved (demodulated) using one of many possible nonlinear operations followed by a low-pass filter. The compressive nonlinearity ofthe visual system is shown to suffice for demodulating such images. Simulations show that HPF images cannot be used to reject the hypothesis that illusions and grouping phenomena are due to low-frequency channels.
Investments in Thermopower Generation : A Real Options Approach for the New Brazilian Electrical Power Regulation

One of the main questions in electricity market deregulation is the aptitude of private capital for investments in power generation. This is especially important in Brazil, whose load has a strong growth trend (≈5% per year). Thermopower is an attractive alternative for expanding generation, as it is complementary in many aspects to hydropower, which supplies most Brazil’s power at a very low price most of the time, but makes the system vulnerable to seasonal water variations. This paper studies the competitiveness of thermopower generation in Brazil under current regulations and assesses under the real options theory approach the conditions for investments in thermopower generation.
SDMA IN MOBILE RADIO SYSTEMS : CAPACITY ENHANCEMENT IN GSM & IS-95

The Space Division Multiple Access (SDMA) technique allows to increase the capacity of a mobile cellular system, exploiting the users spatial separation.This technique can be integrated with conventional access techniques, such as FDMA, TDMA and CDMA; therefore it can be used in all the mobile systems currently operated or to be introduced in the future. In this paper the SDMA technique is deeply analysed. It also evaluates the capacity increase obtainable with SDMA applied to GS M and to a CDMA (Code Division Multiple Access) system, based on Qualcomm IS-95 standard.
Multi-peak solutions for magnetic NLS equations without non{degeneracy conditions

In this work we consider the magnetic NLS equation where , is a magnetic potential, possibly unbounded, is a multi-well electric potential, which can vanish somewhere, f is a subcritical nonlinear term. We prove the existence of a semiclassical multi-peak solution to (0.1), under conditions on the nonlinearity which are nearly optimal.
Preparing for Online and Distance Learning Courses: Factors Affecting Student Learning and Retention

The purpose of this descriptive study is to investigate students’ perceptions of online learning courses at a 4 year mid-level mid-western university and whether or not these perceptions influenced their decision to continue taking online courses or not. The findings of this study concur with Lim (2004) in that thorough preparation prior to online course work can help to curb dropout rates and can better prepare learners for successful completion of the course.
LAFI : LookAhead Mechanism for Energy-Efficient Branch Prediction

To feed the execution core with uninterrupted instruction streams, modern processors access complex branch predictors every clock cycle, incurring high energy consumption. In this paper, we conduct a systematic study on the energy consumption of representative branch predictors, and identify several sources of energy inefficiency. Based on this study, we introduce an improved branch predictor design, called Looking Ahead and FIltering mechanism (LAFI), to reduce branch predictor energy consumption. LAFI employs two simple look-ahead structures to capture most recently executed branches, identify well-behaved branches and detect BTB misses one cycle prior to branch prediction; therefore, it avoids most unnecessary accesses to branch predictors. Experimental results show that LAFI reduces energy consumption in the branch predictor by 48.8% on average. Compared to previous techniques, LAFI saves the predictor energy more effectively and incurs minimal performance overhead.
Putting type annotations to work

We study an extension of the Hindley/Milner system with explicit type scheme annotations and type declarations. The system can express polymorphic function arguments, user-defined data types with abstract components, and structure types with polymorphic fields. More generally, all programs of the polymorphic lambda calculus can be encoded by a translation between typing derivations. We show that type reconstruction in this system can be reduced to the decidable problem of first-order unification under a mixed prefix.
Transmission Cooperative Strategies for MIMO-OFDM Heterogeneous Networks

Mobile traffic in cellular networks is increasing exponentially, mainly due to the use of data intensive ser- vices like video. One way to cope with these demands is to reduce the cell-size by deploying small-cells along the coverage area of the current macro-cell system. The de- ployment of small-cells significantly improves indoor cov- erage. Nevertheless, as additional spectrum licenses are difficult and expensive to acquire it is expected that the macro and small-cells will coexist under the same spec- trum. The coexistence of the two systems results in cross- tier/inter-system interference. In this context, we design several interference alignment based techniques for the downlink of heterogeneous networks, in order to cancel the interference generated from macro-cell at small-cell user terminals. More specifically, in this contribution we design interference alignment methods under different levels of inter-system coordination and the constraint that the per- formance of macro-cell system is kept close to the case where small-cell system is switched-off. Numerical results demonstrate that the proposed methods achieve close to the optimal performance with low overhead.
The retinal mosaics of opsin expression in invertebrates and vertebrates

Color vision is found in many invertebrate and vertebrate species. It is the ability to discriminate objects based on the wavelength of emitted light independent of intensity. As it requires the comparison of at least two photoreceptor types with different spectral sensitivities, this process is often mediated by a mosaic made of several photoreceptor types. In this review, we summarize the current knowledge about the formation of retinal mosaics and the regulation of photopigment (opsin) expression in the fly, mouse, and human retina. Despite distinct evolutionary origins, as well as major differences in morphology and phototransduction machineries, there are significant similarities in the stepwise cell‐fate decisions that lead from progenitor cells to terminally differentiated photoreceptors that express a particular opsin. Common themes include (i) the use of binary transcriptional switches that distinguish classes of photoreceptors, (ii) the use of gradients of signaling molecules for regional specializations, (iii) stochastic choices that pattern the retina, and (iv) the use of permissive factors with multiple roles in different photoreceptor types. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 71: 1212–1226, 2011
Institutional collaboration and competition in community-based education

We sought to determine whether competition for community-based training sites exists among health professions schools, and to examine faculty and senior administrators' perspectives on institutional collaboration for community-based education. Eight academic health centers (AHCs) in the USA were selected by objective criteria for their significant community involvement. Chief executive officers, vice chancellors, deans, and the individuals responsible for community-based education, research and community service responded to written surveys. The overall response rate was 79% (n = 91). Responses were subjected to quantitative and qualitative analyses. Leaders of community-based education reported that ‘competition for community-based training sites’ is a barrier to community involvement. ‘Competition for community-based training sites’ was positively related to ‘call for increasing percentage of graduates to enter primary care careers’ (0.30, p < 0.01) and negative related to ‘collaboration exists between the community and your school/AHC’ ( − 0.28, p < 0.05). Respondents reported that a moderate level of collaboration across schools exists. While medical school respondents reported having collaborative relationships with other health professions schools and with the community, nursing respondents reported medicine's performance at a significantly lower level. Public health and nursing faculty reported that they are competing with medical schools for sites they had traditionally used for their students. Competition for sites is an unintended outcome of the increased emphasis on community-based education in health professions curricula. We recommend AHCs form joint committees across schools to effectively address community-based sites as a limited resource, and to consider a wider range of community-based organizations as training partners.
Qualidade de Vida e Nível de Atividade Física de Trabalhadores com Diferentes Tempos de Serviço Life Quality and Physical Activity Level of Workers with Different Working Times

Objective: To describe workers' life quality and physical activity level. Complementarily, the employees' working time in the company was associated to their physical activity level and compared to their life quality. Materials and Methods: The sample was composed by 375 workers of both genders from a national company of electrical energy in Pernambuco. Then, those workers were subdivided into two groups according to their working time in the company: up to 15 years (n=166) with age mean of 36.08±6.80 years and more than 15 years (n=209) with age mean of 55.37± 5.17 years. Statistical analysis was made using Mann Whitney and Chi-square tests with p <0.05. Results: The employees having more working time presented better levels in the physical (p<0.05), psychological (p<0.01) and environmental (p<0.05) domains. The associative analysis between the physical activity level and the working time has revealed that the workers having more working time were more physically actives (X 2
Short quasi-cyclic LDPC codes from convolutional codes

We search for good regular quasi-cyclic (QC) LDPC codes with J = 2 ones in each column. In order to simplify the search, QC LDPC codes are represented in the form of tail-biting (TB) convolutional codes. A modified BEAST algorithm is used for finding the free distance (minimum distance) and the girth of both parent convolutional and block LDPC codes. Representations of known bipartite graphs and LDPC based on finite geometries in the form of TB convolutional codes are found. This approach is further generalized for J = 3 QC LDPC codes. Examples of good short LDPC codes with large girth and minimum distance are given. For example, we present a rate 2=5 J = 3 QC LDPC (225, 92)- code with girth 8 and minimum distance 24.
On the development of global plasma-ionosphere FDTD algorithms for electromagnetic calculations in the Earth-ionosphere system

This paper reports the development of global FDTD models incorporated with a quasi-real anisotropic ionosphere consisting of magnetized cold plasmas. Compared to the existing global models utilizing simple conductivity ionospheric profiles, the algorithms reported in this paper can sufficiently extend the global-scale electromagnetic simulations to much higher altitudes as the physics introduced by the spatially-varied ionospheric plasmas and the geomagnetic field can be fully included in calculations.
How visual attention is modified by disparities and textures changes?

The 3D image/video quality of experience is a multidimensional concept that depends on 2D image quality, depth quantity and visual comfort. The relationship between these parameters is not yet clearly defined. From this perspective, we aim to understand how texture complexity, depth quantity and visual comfort influence the way people observe 3D content in comparison with 2D. Six scenes with different structural parameters were generated using Blender software. For these six scenes, the following parameters were modified: texture complexity and the amount of depth changing the camera baseline and the convergence distance at the shooting side. Our study was conducted using an eye-tracker and a 3DTV display. During the eye-tracking experiment, each observer freely examined images with different depth levels and texture complexities. To avoid memory bias, we ensured that each observer had only seen scene content once. Collected fixation data were used to build saliency maps and to analyze differences between 2D and 3D conditions. Our results show that the introduction of disparity shortened saccade length; however fixation durations remained unaffected. An analysis of the saliency maps did not reveal any differences between 2D and 3D conditions for the viewing duration of 20 s. When the whole period was divided into smaller intervals, we found that for the first 4 s the introduced disparity was conducive to the section of saliency regions. However, this contribution is quite minimal if the correlation between saliency maps is analyzed. Nevertheless, we did not find that discomfort (comfort) had any influence on visual attention. We believe that existing metrics and methods are depth insensitive and do not reveal such differences. Based on the analysis of heat maps and paired t-tests of inter-observer visual congruency values we deduced that the selected areas of interest depend on texture complexities.
Query Performance Prediction for Aspect Weighting in Search Result Diversification

Accurate estimation of query aspect weights is an important issue to improve the performance of explicit search result diversification algorithms. For the first time in the literature, we propose using post-retrieval query performance predictors (QPPs) to estimate, for each aspect, the retrieval effectiveness on the candidate document set, and leverage these estimations to set the aspect weights. In addition to utilizing well-known QPPs from the literature, we also introduce three new QPPs that are based on score distributions and hence, can be employed for online query processing in real-life search engines. Our exhaustive experiments reveal that using QPPs for aspect weighting improves almost all state-of-the-art diversification algorithms in comparison to using a uniform weight estimator. Furthermore, the proposed QPPs are comparable or superior to the existing predictors in the context of aspect weighting.