Miracle-dz/UniFAR-FTUs huggingface dataset:
A Study on the Implementation of Tridiagonal Systems Solvers Using a GPU

In recent years the use of secondary hardware to accelerate computation of general-purpose problems has emerged as an alternative to traditional high performance computing (HPC) hardware. Specially, the use of graphics processors (GPUs) in the field of HPC has grown given their inherent parallel architecture and low cost. In a previous work, we have studied a preliminary implementation of the cyclic reduction method to tackle tridiagonal linear systems. In this article, we improve our previous implementation in order to accelerate the tridiagonal solvers on GPU using efficient memory techniques, such as pinned memory and coalesced access. The article also presents the implementation of parallel cyclic reduction method on GPU. We analyze and implement several methods for solving tridiagonal systems on GPUs. These implementations were evaluated on different hardware platforms, obtaining significant accelerations, allowing speedups of 3× on a NVIDIA C1060 GPU. The obtained results demonstrate that this new proposal can achieve significant speedup values when compared to an implementation of Thomas method on CPU and our previous GPU implementation.
When Visual Programs are Harder to Read than Textual Programs

Claims for the virtues of visual programming languages have generally been strong, simple-minded statements that visual programs are inherently better than textual ones. They have paid scant attention to previous empirical literature showing difficulties in comprehending visual programs. This paper reports comparisons between the comprehensibility of textual and visual programs, drawing on the methods developed by Green (1977) for comparing detailed comprehensibility of conditional structures. The visual language studied was LabView, a circuit-diagram-like language which can express conditionals either as ‘forwards’ structures (condition implies action, with nesting) or as ‘backwards’ structures (action is governed by conditions, with boolean operators in place of nesting). Green (1977) found that forwards structures gave relatively better access to ‘sequential’ information, and Gilmore and Green (1984) showed ‘backwards’ structures gave relatively better access to ‘circumstantial’ information. These differences were supported in the present study for both text and graphics presentations. Overall, however, the visual programs were harder to comprehend than the textual ones, a strong effect which was found for every single subject, even though the subjects were either experienced LabView users or else experienced users of circuit diagrams. Our explanation is that the structure of the graphics in the visual programs is, paradoxically, harder to scan than in the text version.
Hybrid Energy Storage with Supercapacitor for Cost-Efficient Data Center Power Shaving and Capping

Recent studies have proposed to dynamically reshape the power demand curve of a data center (i.e., power shaving) with energy storage devices, particularly uninterruptible power supply (UPS) batteries. Power shaving can be used to limit the peak power demand in a data center, in order to reduce both the power infrastructure investment (i.e., cap-ex) and the electricity bills (i.e., op-ex). However, power shaving requires the UPS batteries to be frequently charged/discharged, which is known to compromise the battery lifetime and availability. This paper presents a detailed quantitative study that explores different options to integrate supercapacitor (SC) with batteries for cost-efficient energy storage. Compared with batteries, SC allows more charge/discharge cycles and has a higher power density, which are desirable for fast power shaving. However, SC also has undesirable characteristics (e.g., relatively high self-discharging rate and cost). Therefore, we quantitatively compare three possible energy storage options (i.e., Battery-only, SC-only, and Battery+SC ) in detail, with different SC self-discharging rate assumptions. SC options (SC-only and Battery+SC) are shown to be more cost-efficient designs, saving the energy storage cost by 34 percent, on average, compared with Battery-only. For a 10 MW data center in a 10-year period, the savings can be converted to $3 M in total cost of ownership (TCO) reduction by allowing more servers to be deployed. In addition, we also propose the integration of energy storage with dynamic voltage and frequency scaling (DVFS) to cap the peak power demand (i.e., power capping). Specifically, we comparatively study four power capping algorithms and discuss their applicable scenarios. Finally, we introduce our proof-of-concept SC physical testbed and present preliminary hardware testing results.
Interpreting the Morphology of Diffuse Light around Satellite Galaxies

Recent observations of surface brightness distributions of both Milky Way and M31 satellite galaxies have revealed many instances of sudden changes or breaks in the slope of the surface brightness profiles (at some break radius rbreak). These breaks are often accompanied by increasingly elliptical isophotes and sometimes by isophote twisting. We investigate the hypothesis of a tidal origin for these features by applying the same ellipse-fitting techniques that are used on observed galaxies to numerical simulations of the destruction of satellites, represented by spherical, single-component systems. We examine how observed quantities such as rbreak, ellipticity e, and position angle ϕ of the fitted ellipses and amplitude of the extra-break population vary with the satellite's orbital eccentricity and phase, as well as our viewpoint relative to the orbit. We also look at orbit and viewpoint dependence of the rate of change of the latter three quantities with radius. We find that there are trends with orbital phase and eccentricity in all observed quantities, many of which are preserved through a wide variety of viewing angles. In particular, a generic feature of all simulations is a depletion zone just interior to an excess zone, regions in which the surface brightness is lower and higher, respectively, than the initial profile. A clear interpretation of any individual image, however, is likely to be hampered by the dependence of the observable features on these multiple parameters. For example, breaks can be excited by several physical processes and can occur well within the bound satellite population. Nevertheless, we do find we can place loose constraints on the tidal radius, mass-loss rate, orbital type and phase of the satellite, and nature of breaks, using photometric data alone.
Simulation Builds Empathy in Future Social Entrepreneurs

What does this mean for those who teach social entrepreneurship? Unfortunately little research has focused done on empathy or on how to teach social entrepreneurship (Brock & Steiner, 2008). This is troubling given the distinctive challenge of educating future social entrepreneurs (Tracey & Phillips, 2007). To educate students about social entrepreneurship, scholars have suggested a number of pedagogical approaches, ranging from in-class cases to cocurricular creation of social ventures (Tracey & Phillips, 2007; Smith, Barr, Barbosa & Kickul, 2008; Brock & Steiner, 2008). Some are more hands-on than others, and are more or less doable within a course's time constraints.
The Accounting Network: How Financial Institutions React to Systemic Crisis

The role of Network Theory in the study of the financial crisis has been widely spotted in the latest years. It has been shown how the network topology and the dynamics running on top of it can trigger the outbreak of large systemic crisis. Following this methodological perspective we introduce here the Accounting Network, i.e. the network we can extract through vector similarities techniques from companies’ financial statements. We build the Accounting Network on a large database of worldwide banks in the period 2001–2013, covering the onset of the global financial crisis of mid-2007. After a careful data cleaning, we apply a quality check in the construction of the network, introducing a parameter (the Quality Ratio) capable of trading off the size of the sample (coverage) and the representativeness of the financial statements (accuracy). We compute several basic network statistics and check, with the Louvain community detection algorithm, for emerging communities of banks. Remarkably enough sensible regional aggregations show up with the Japanese and the US clusters dominating the community structure, although the presence of a geographically mixed community points to a gradual convergence of banks into similar supranational practices. Finally, a Principal Component Analysis procedure reveals the main economic components that influence communities’ heterogeneity. Even using the most basic vector similarity hypotheses on the composition of the financial statements, the signature of the financial crisis clearly arises across the years around 2008. We finally discuss how the Accounting Networks can be improved to reflect the best practices in the financial statement analysis.
A nobel key-search method for side channel attacks based on pattern recognition

Differential power analysis (DPA) has been known as an efficient attack for finding secret keys of cryptosystems but its efficiency may be lowered due to the misalignment of the acquired signals. Though the misalignment problem has been now solvable by various successful approaches in DPA, a lot of power traces are still required to find correct keys. Since the required number of power traces is directly connected with the efficiency of SCAs, we propose a key-search method even with relatively reduced number of power traces based on recognizing special patterns of the signal caused by cryptographic operations. Experimental results show that the proposed method is able to search correct keys with much smaller number of traces than the minimum number of traces with which the conventional methods of the energy-based DPA and frequency-based DPA succeed in finding keys.
Multi-view Face Analysis Based on Gabor Features

Facial analysis has attracted much attention in the technology for human-machine interface. Different methods of classification based on sparse representation and Gabor kernels have been widely applied in the fields of facial analysis. However, most of these methods treat face from a whole view standpoint. In terms of the importance of different facial views, in this paper, we present multi-view face analysis based on sparse representation and Gabor wavelet coefficients. To evaluate the performance, we conduct face analysis experiments including face recognition (FR) and face expression recognition (FER) on JAFFE database. Experiments are conducted from two parts: (1) Face images are divided into three facial parts which are forehead, eye and mouth. (2) Face images are divided into 8 parts by the orientation of Gabor kernels. Experimental results demonstrate that the proposed methods can significantly boost the performance and perform better than the other methods.
Resolution limit in complex network community detection with Potts model approach

According to Fortunato and Barthélemy, modularity-based community detection algorithms have a resolution limit, i.e., small communities in a large network are invisible. We generalize their work and show that the q-state Potts community detection method introduced by Reichardt and Bornholdt has also a resolution limit. The model contains a parameter by which this limit can be tuned, but no a priori principle is known to select the proper value. Single global optimization criteria do not seem capable for detecting all communities if their sizes have a broad distribution. PACS. 89.75. -k Complex systems – 89.75. Hc Networks and genealogical trees – 89.75. Fb Structures and organization in complex systems – 89.65. -s Social and economic systems
Color image sharpening based on nonlinear reaction-diffusion

Previously we have presented a selective sharpening method for monochrome images. Our method is based on the simultaneous nonlinear reaction-diffusion time-evolution equipped with a nonlinear diffusion term, a reaction term and an overshooting term, and can sharpen degraded edges blurred by several causes without increasing the visibility of random noise. This paper extends our method to selective sharpening of color images. As to the how to extend it, we take into accounts two variations about the treatment of three color components and the selection of the color space. By experiments, we quantitatively evaluate performance of these variations. The best performance is achieved by the collective treatment of color components based on the simultaneous full-nonlinear reaction-diffusion time-evolution, and blurred color edges are sharpened selectively much better than by the existing methods such as the adaptive peaking method.
Lender Banks' Provision of Overseas Market Information: Evidence from Japanese small and medium-sized enterprises' export dynamics

This paper examines how Japanese firms' export decision is affected by the availability of information on export markets, focusing on whether the availability of such information has a different impact on the export decision between large firms and small and medium-sized enterprises (SMEs). In contrast to existing studies which solely focus on information sharing among firms, we are interested in the role of firms' lender banks as an additional source of information. Specifically, using a unique dataset containing information not only on firms' export activities but also on their lender banks' exposure to other exporting firms as well as the lender banks' own overseas activities, we find that information provisions by lender banks positively affect SMEs' decision to start exporting and the range of destinations to which they export. Such information provisions from lender banks also reduce the likelihood that exporter firms exit from export markets. The export-to-sales ratio of exporter firms, however, is not affected by such information provisions. We also find that the importance of the information provisions by lender banks on SMEs' export decision crucially depends on the type of products (i.e., differentiated or homogeneous) produced in the industries to which the firms belong. These results imply that information on foreign markets provided by lender banks substantially reduces the fixed entry costs associated with starting exporting and entering new export markets as well as firms' costs associated with continuing to export.
Log-based indexing to improve web site search

Despite the success of global search engines, web site search is still problematic in its retrieval accuracy. In this paper, we try to improve the performance of the site search by combining a new source of evidence from web server logs. We propose a novel approach of using server log analysis to extract terms to build the web page index. Then, this log-based index is combined with the text-based and anchor-based index to provide a more complete view on the page content. Experiments have shown that it could improve the effectiveness of the web site search significantly.
E cient Address Generation for A ne Subscripts inData-Parallel

This paper presents an eecient compilation technique to generate the local memory access sequences for block-cyclically distributed array references with aane subscripts in data-parallel programs. For the memory accesses of an array reference with aane subscript within a two-nested loop, there exist repetitive patterns both at the outer and inner loops. We use tables to record the memory accesses of repetitive patterns. According to these tables, a new start-computation algorithm is proposed to compute the starting elements on a processor for each outer loop iteration. The complexities of the table constructions are O(k + s 2), where s 2 is the access stride for the inner loop. After tables are constructed, generating each starting element for each outer loop iteration can run in O(1) time. For the repetitive pattern of outer loop, Moreover, we also discover that the repetitive iterations for outer loop are Pk= gcd(P k; s 1) instead of Pk, where s 1 is the access stride for the outer loop. Therefore, the total complexity to generate the local memory access sequences for a block-cyclically distributed array with aane subscript in a two-nested loop is O(Pk gcd(P k;s1) + k + s 2).
Regulation of protease nexin-1 expression in cultured Schwann cells is mediated by angiotensin II receptors

Protease nexin-1 (PN-1) is a potent inhibitor of serine proteases, such as thrombin and plasminogen activators, which is secreted into the extracellular space. Since PN-1 is induced following lesion of the sciatic nerve, the effect of substances known to accumulate at the site of injury was examined in primary cultures of Schwann cells. Among the cytokines, growth factors, mitogens, neurotrophins, and neuroactive peptides analyzed, only angiotensin II (Ang II), calcitonin gene- related peptide (CGRP), and vasoactive intestinal peptide (VIP) were found to regulate the expression of PN-1 on Schwann cells. While Ang II and CGRP caused downregulation, VIP acted as a positive modulator of PN- 1. Displacement of Ang II binding using the selective ligands losartan and CGP 42112 led to a severalfold increase of PN-1 protein and mRNA over basal levels, indicating that the observed effect was mediated by specific binding sites. Indeed, the presence of AT1 and AT2 angiotensin receptor subtypes was demonstrated in cultured Schwann cells as well as in the rat sciatic nerve. Moreover, the detection of angiotensinogen- and renin-mRNA in these cultures suggested an endogenous production of Ang II. This data identified one of the mechanisms regulating PN-1 synthesis. Altogether our results indicate that neuropeptides can differentially control the proteolytic activity of the microenvironment, providing new aspects of neuron-glia interactions in the intact tissue and following nerve injury.
Pipelined Block-Serial Decoder Architecture for Structured Ldpc Codes

We present a pipelined block-serial decoder architecture for structured LDPC codes, implementing the layered-mode belief-propagation. We introduce the concept of LLR-update and mirror memory to enforce a pipelined decoding schedule. The pipelined architecture improves the latency of the LDPC decoder by about 2x-3x and has negligible performance loss when implemented with clever layer scheduling. We also present a low-complexity check-node architecture suitable for block-serial processing and utilize the properties of the min approximation to significantly reduce the memory requirement. The proposed architecture is suitable for mobile devices with data-rates of tens of mbps
Chopping down the syntax tree: What constructions can do instead

Word order, argument structure and unbounded dependencies are among the most important topics in linguistics because they touch upon the core of the syntax-semantics interface. One question is whether “marked” word order patterns, such as The man I talked to vs. I talked to the man, require special treatment by the grammar or not. Mainstream linguistics answers this question affirmatively: in the marked order, some mechanism is necessary for “extracting” the man from its original argument position, and a special placement rule (e.g. topicalization) is needed for putting the constituent in clause-preceding position. This paper takes an opposing view and argues that such formal complexity is only required for analyses that are based on syntactic trees. A tree is a rigid data structure that only allows information to be shared between local nodes, hence it is inadequate for non-local dependencies and can only allow restricted word order variations. A construction, on the other hand, offers a more powerful representation device that allows word order variations – even unbounded dependencies – to be analyzed as the side-effect of how language users combine the same rules in different ways in order to satisfy their communicative needs. This claim is substantiated through a computational implementation of English argument structure constructions in Fluid Construction Grammar that can handle both comprehension and formulation.
Two-choice Digging Task in Mouse for Studying the Cognitive Flexibility

[Abstract] Cognitive flexibility, the higher-order cognition involving reversal learning, has been defined as having the ability to shift one’s previous thoughts or actions to new situations depending on situational demands. Studies of neuropsychiatric disorders such as autism spectrum disorder (ASD) showed that restricted and repetitive patterns of activities are associated with the impairments of cognitive flexibility. Some behavioral tasks including attentional set-shifting task are used to assess cognitive flexibility in mouse models for psychiatric disorders (Birrell and Brown, 2000; Colacicco et al., 2002). Here we present a two-choice digging test, which is simplified and modified from set-shifting task, for using mice to study the reversal learning (Huang et al., 2014).
Commentary on: Are we overpathologizing everyday life? A tenable blueprint for behavioral addiction research

Billieux et al. (2015) propose that the recent proliferation of behavioral addictions has been driven by deficiencies in the underlying research strategy. This commentary considers how pathological gambling (now termed gambling disorder) traversed these challenges to become the first recognized behavioral addiction in the DSM-5. Ironically, many similar issues continue to exist in research on gambling disorder, including question-marks over the validity of tolerance, heterogeneity in gambling motives, and the under-specification of neuroimaging biomarkers. Nevertheless, I contend that the case for gambling disorder as a behavioral addiction has been bolstered by the existence of clear and consistent functional impairment (primarily in the form of debt), coupled with the development of a public health approach that has given emphasis to product features (i.e. the structural characteristics of gambling forms) as much as individual dispositions (the ‘addictive personality’).
Erratum: Luminosity function, sizes and FR dichotomy of radio-loud AGN

This erratum corrects a number of formulae containing mistakes in the paper 'Luminosity function, sizes and FR dichotomy of radio-loud AGN', 2007, MNRAS, v. 381, p.1548. The corrections do not alter any of the conclusions in the original paper.