Miracle-dz/UniFAR-FTUs huggingface dataset:
Non-transparent recommender system evaluation leads to misleading results

Recommender systems have become a ubiquitous feature on the World Wide Web. Today, most websites use some form of recommendation to heighten their users’ experience. They do so by analyzing what items users have interacted with previously and analyze the interaction patterns generated. In order to identify whether one recommendation approach performs better than another, various evaluation techniques are employed [1, 3]. These techniques usually focus on how accurate, or close to the user’s preferences, the recommendations are; in simple terms: the better the evaluation scores, the better the recommender. However, when comparing the results of one recommender system to another, it is difficult to compare results verbatim due to the many options in design and implementation of an evaluation strategy. Additionally, implementational differences in the underlying recommendation framework can increase the comparison difficulty. In our work [2], we investigate the discrepancies between common open source recommender system frameworks and highlight the difference in evaluation protocols – even when the same evaluation metrics are employed, evidencing differences in their implementation. In order to create a fair comparison, we additionally generate the same metrics using a transparent evaluation protocol and propose a controlled evaluation protocol where these aspects are clearly specified and tested. Our work shows large differences in recommendation accuracy across frameworks, and even larger differences when comparing the results from the controlled evaluation. The implication is that comparing the results from several recommender systems is often infeasible, unless a strict and transparent protocol is followed. BODY Evaluation of recommender systems is often misleading, transparent protocols should be used and reported by industry and academia.
Modeling of Floating-Body effect on Negative Bias Temperature Instability degradation of double-gate MOSFETs

In this paper, the effect of Floating-Body (FB) on the Negative Bias Temperature Instability (NBTI) degradation of undoped double-gate (DG) MOSFETs is modeled and investigated through solving the one-dimensional (1-D) Poisson's equation considering the NBTI effect in the inversion region. The accuracy of the model is verified by the finite difference method (FDM). The results of the model are in very good agreement with those of the numerical method. These results show that in FB devices, the accumulation of the NBTI stress generated electrons in the device floating body, leads to a decrease in the body potential, oxide field, and inversion charge and as a result decrease the generation of interface traps and degradation of device. Moreover, in devices with thinner body, the volume density of generated electrons is larger which result in more degradation of the oxide field and inversion charge density in these devices.
Direct power and torque control for three-level NPC based PWM ac/dc/ac converter

This paper presents a new control scheme for three-level neutral point clamped (NPC) based PWM ac/dc/ac converter. The direct power control (DPC) for front-end three-level PWM rectifier and direct torque control (DTC) for back-end three-level PWM inverter-fed induction motor are adopted respectively. A power feed-forward control loop from inverter to rectifier side is introduced to obtain better dynamic performance for the dc-link. Simulation results show that with the proposed control scheme, the three-level NPC based PWM ac/dc/ac converter exhibits excellent dynamic performance, and can minimize dc-bus voltage fluctuations.
Experimental Evaluation of Braided EKF for Sensorless Control of Induction Motors

Temperature- and frequency-dependent variations of the rotor (R'r) and stator (Rs) resistances pose a challenge in the accurate estimation of flux and velocity in the sensorless control of induction motors (IMs) over a wide speed range. Solutions have been sought to the problem by signal injection and/or by the use of different algorithms for the different parameters and states of the same motor. In this paper, a novel Extended-Kalman-Filter (EKF)-based estimation technique is developed for the solution of the problem based on the consecutive operation of two EKF algorithms at every time step. The proposed ldquobraidedrdquo EKF technique is experimentally tested under challenging parameter and load variations in a wide speed range, including low speed. The results demonstrate a significantly increased accuracy in the estimation of Rs and R'r, as well as load torque, flux, and velocity in transient and steady state, when compared with single EKFs or other approaches taken to estimate these parameters and states in the sensorless control of IMs. The improved results also motivate the utilization of the new estimation approach in combination with a variety of control methods which depend on accurate knowledge of a high number of parameters and states.
Measurements of the steady streaming flow around oscillating spheres using three dimensional particle tracking velocimetry

Granular particles vibrated in a fluid have been found to exhibit self-organization with attractive and repulsive interactions between the particles. These interactions have been attributed to the steady streaming flow around oscillating particles. Here we examine the steady streaming flow surrounding a vertically oscillating sphere using three-dimensional particle tracking velocimetry. We present measurements of the flow with the sphere far from boundaries, close to the bottom wall of the tank, and near another oscillating sphere. For parameters of interest for granular self-organization, the flow around a single sphere far from boundaries differs significantly from an analytical calculation that has been applied to granular organization. Measured positions of the stagnation point support previously observed scaling at small amplitudes, and demonstrate how this scaling changes at large amplitudes. When the sphere is oscillated near the bottom wall, the topology of the flow changes, resulting in a larger .
Using Overlapping Distributions to Deal with Face Pose Mismatch

Representing the face as a distribution of freely moving patches, which we refer to as a “free-parts” representation, has recently demonstrated some benefit in the task of face verification. This benefit can be largely attributed to the representation’s natural ability to deal with local appearance variation within the face. Hitherto, a major limitation that has hindered the wider adoption of this type of facial representation, for the task of face verification, has been its poor ability to take advantage of prior knowledge concerning mismatches in context; such as pose. This paper goes some way to alleviating these limitations by making two novel contributions: (i) Demonstrating that free-parts distributions of a client’s face for different poses overlap to such a degree that a considerable amount of discrimination is preserved in the intersection. (ii) Through the off-line estimation of subject-independent pose dependent priors, an alternative to the canonical log-likelihood measure can be employed that takes advantage of this intersection and is less sensitive to mismatch in the presence of pose variation.
FINITE ELEMENT MODELING FOR INFRARED THERMOGRAPHY OF GFRP BRIDGE DECKS

Glass Fiber Reinforced Polymer (GFRP) composite bridge decks are increasingly being used as replacements for old concrete decks and for new construction. The service performance of the GFRP bridge decks can be adversely affected by the formation of debonds between the wearing surface and the underlying bridge deck. Past experimental studies by the authors have shown the usefulness of the infrared thermography technique in detecting the subsurface debonds prior to maintenance and rehabilitation work. This paper investigates the use of finite element (FE) heat transfer modeling to predict infrared thermography images from GFRP bridge decks with subsurface debonds. The paper includes measurement of thermal properties of the GFRP bridge deck and the wearing surface, and heat transfer FE modeling of decks with debonds of different thicknesses. The results show that FE modeling can be a useful tool for predicting surface temperature profile under different heating conditions and debond sizes. Such predictions c.
On embeddability of modular robot designs

We address the problem of detecting embeddability of modular robots: namely, to decide automatically whether a given modular robot design can simulate the functionality of a seemingly different design. To that end, we introduce a novel graph representation for modular robots and formalize the notion of embedding through topological and kinematic conditions. Based on that, we develop an algorithm that decides embeddability when the two involved designs have tree topologies. Our algorithm performs two passes and involves dynamic programming and maximum cardinality matching. We demonstrate our approach on real modular robots and show that we can detect embeddability of complex designs efficiently.
Fuzzy Goal Programming Approach to Solve Linear Multilevel Programming Problems using Genetic Algorithm

paper introduces a priority based fuzzy goal programming (FGP) method for modelling and solving multilevel programming problem (MLPP) through genetic algorithm (GA). In model formulation, the individual best solution of objectives of each of the decision makers (DMs) is determined by using the GA method for fuzzy description of the objectives. Then, tolerance membership functions of the defined fuzzy goals are constructed for measuring the degree of satisfaction of goal achievement and there by degree of optimality of the decision vectors controlled by the higher level DMs. In the executable FGP model, minimization of the under-deviational variables of the defined membership goals with highest membership value (unity) as the aspiration levels of them on the basis of pre- emptive priority is taken into consideration in the decision making context. In the solution process, sensitivity analysis with variations of priority structure of model goals is performed and then Euclidean distance function is used to identify the appropriate priority structure under which the most satisfactory decision can be reached in the decision making horizon. In the proposed GA scheme, roulette-wheel selection scheme, single point crossover and uniform mutation are adopted in the decision search process with regard to reach a satisfactory solution in the proposed hierarchical decision system. The effective use of the proposed approach is illustrated through a numerical example. Performance comparisons are also made to highlight the superiority of the proposed approach over the approaches studied previously.
Title: Spatial Integration in Mouse Primary Visual Cortex 1 2 Spatial Integration in Mouse Primary

Title: Spatial integration in mouse primary visual cortex 1 2 Authors and author addresses: 3 Agne Vaiceliunaite1,2, Sinem Erisken1, Florian Franzen1, Steffen Katzner1, and 4 Laura Busse1 5 6 1Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, 7 Germany 8 2Department of Neurobiology Biophysics, Faculty of Natural Sciences, Vilnius 9 University, Lithuania 10 11 Running head: Spatial integration in mouse visual cortex 12 13 Contact information: 14 Laura Busse 15 Centre for Integrative Neuroscience 16 University of Tübingen 17 Otfried-Müller-Str. 25 18 72076 Tübingen 19 Germany 20 laura.busse@cin.uni-tuebingen.de 21 22 Articles in PresS. J Neurophysiol (May 29, 2013). doi:10.1152/jn.00138. 2013
Rental Harmony: Sperner's Lemma in Fair Division

My friend’s dilemma was a practical question that mathematics could answer, both elegantly and constructively. He and his housemates were moving to a house with rooms of various sizes and features, and were having trouble deciding who should get which room and for what part of the total rent. He asked, “Do you think there’s always a way to partition the rent so that each person will prefer a different room? ” As we shall see, with mild assumptions, the answer is yes. This rent-partitioning problem is really a kind of fair-division question. It can be viewed as a generalization of the age-old cake-cutting problem, in which one seeks to divide a cake fairly among several people, and the chore-division problem, posed by Martin Gardner in [6, p. 124], in which one seeks to fairly divide an undesirable entity, such as a list of chores. Lately, there has been much interest in fair division (see, for example, the recent books [3] and [11]), and each of the related problems has been treated before (see [1], [4], [10]). We wish to explain a powerful approach to fair-division questions that unifies these problems and provides new methods for achieving approximate envy-free divisions, in which each person feels she received the “best” share. This approach was carried out by Forest Simmons [13] for cake-cutting and depends on a simple combinatorial result known as Sperner’s lemma. We show that the Sperner’s lemma approach can be adapted to treat chore division and rent-partitioning as well, and it generalizes easily to any number of players. From a pedagogical perspective, this approach provides a nice, elementary demonstration of how ideas from many pure disciplines—combinatorics, topology, and analysis—can combine to address a real-world problem. Better yet, the proofs can be converted into constructive fair-division procedures.
Health-care sector and complementary medicine: practitioners’ experiences of delivering acupuncture in the public and private sectors

Aim The aim was to identify similarities and differences between private practice and the National Health Service (NHS) in practitioners’ experiences of delivering acupuncture to treat pain. We wished to identify differences that could affect patients’ experiences and inform our understanding of how trials conducted in private clinics relate to NHS clinical practice. Background Acupuncture is commonly used in primary care for lower back pain and is recommended in the National Institute for Health and Clinical Excellence's guidelines. Previous studies have identified differences in patients’ accounts of receiving acupuncture in the NHS and in the private sector. The major recent UK trial of acupuncture for back pain was conducted in the private sector. Methods Semi-structured qualitative interviews were conducted with 16 acupuncturists who had experience of working in the private sector (n = 7), in the NHS (n =3), and in both the sectors (n = 6). The interviews lasted between 24 and 77 min (median=49 min) and explored acupuncturists’ experiences of treating patients in pain. Inductive thematic analysis was used to identify similarities and differences across private practice and the NHS. Findings The perceived effectiveness of acupuncture was described consistently and participants felt they did (or would) deliver acupuncture similarly in NHS and in private practice. In both the sectors, patients sought acupuncture as a last resort and acupuncturist–patient relationships were deemed important. Acupuncture availability differed across sectors: in the NHS it was constrained by Trust policies and in the private sector by patients’ financial resources. There were greater opportunities for autonomous practice in the private sector and regulation was important for different reasons in each sector. In general, NHS practitioners had Western-focussed training and also used conventional medical techniques, whereas private practitioners were more likely to have Traditional Chinese training and to practise other complementary therapies in addition to acupuncture. Future studies should examine the impact of these differences on patients' clinical outcomes.
Detecting Overlapping Communities from Local Spectral Subspaces

Based on the definition of local spectral subspace, we propose a novel approach called LOSP for local overlapping community detection. Using the power method for a few steps, LOSP finds an approximate invariant subspace, which depicts the embedding of the local neighborhood structure around the seeds of interest. LOSP then identifies the local community expanded from the given seeds by seeking a sparse indicator vector in the subspace where the seeds are in its support. We provide a systematic investigation on LOSP, and thoroughly evaluate it on large real world networks across multiple domains. With the prior information of very few seed members, LOSP can detect the remaining members of a target community with high accuracy. Experiments demonstrate that LOSP outperforms the Heat Kernel and PageRank diffusions. Using LOSP as a subroutine, we further address the problem of multiple membership identification, which aims to find all the communities a single vertex belongs to. High F1 scores are achieved in detecting multiple local communities with respect to arbitrary single seed for various large real world networks.
Reductions in the Cardiac Transient Outward K+ Current Ito Caused by Chronic β-Adrenergic Receptor Stimulation Are Partly Rescued by Inhibition of Nuclear Factor κB*

The fast transient outward potassium current (Ito,f) plays a critical role in the electrical and contractile properties of the myocardium. Ito,f channels are formed by the co-assembly of the pore-forming α-subunits, Kv4.2 and Kv4.3, together with the accessory β-subunit KChIP2. Reductions of Ito,f are common in the diseased heart, which is also associated with enhanced stimulation of β-adrenergic receptors (β-ARs). We used cultured neonatal rat ventricular myocytes to examine how chronic β-AR stimulation decreases Ito,f. To determine which downstream pathways mediate these Ito,f changes, adenoviral infections were used to inhibit CaMKIIδc, CaMKIIδb, calcineurin, or nuclear factor κB (NF-κB). We observed that chronic β-AR stimulation with isoproterenol (ISO) for 48 h reduced Ito,f along with mRNA expression of all three of its subunits (Kv4.2, Kv4.3, and KChIP2). Inhibiting either CaMKIIδc nor CaMKIIδb did not prevent the ISO-mediated Ito,f reductions, even though CaMKIIδc and CaMKIIδb clearly regulated Ito,f and the mRNA expression of its subunits. Likewise, calcineurin inhibition did not prevent the Ito,f reductions induced by β-AR stimulation despite strongly modulating Ito,f and subunit mRNA expression. In contrast, NF-κB inhibition partly rescued the ISO-mediated Ito,f reductions in association with restoration of KChIP2 mRNA expression. Consistent with these observations, KChIP2 promoter activity was reduced by p65 as well as β-AR stimulation. In conclusion, NF-κB, and not CaMKIIδ or calcineurin, partly mediates the Ito,f reductions induced by chronic β-AR stimulation. Both mRNA and KChIP2 promoter data suggest that the ISO-induced Ito,f reductions are, in part, mediated through reduced KChIP2 transcription caused by NF-κB activation.
Timeline-based information assimilation in multimedia surveillance and monitoring systems

Most surveillance and monitoring systems nowadays utilize multiple types of sensors. However, due to the asynchrony among and diversity of sensors, information assimilation - how to combine the information obtained from asynchronous and multifarious sources is an important and challenging research problem. In this paper, we propose a hierarchical probabilistic method for information assimilation in order to detect events of interest in a surveillance and monitoring environment. The proposed method adopts a bottom-up approach and performs assimilation of information at three different levels - media-stream level, atomic-event level and compound-event level.To detect an event, our method uses not only the current media streams but it also utilizes their two important properties - first, accumulated past history of whether they have been providing the concurring or contradictory evidences, and - second, the system designer's confidence in them. A compound event, which comprises of two or more atomic-events, is detected by first estimating probabilistic decisions for the atomic-events based on individual streams, and then by aligning these decisions along a timeline and hierarchically assimilating them. The experimental results show the utility of our method.
Closed-form error estimates for the numerical solution of Fredholm integral equations of the second kind

Closed-form algebraic formulae are derived for the local error incurred in the numerical solution of integral equations by iterated collocation methods, the analysis being illustrated by application to Fredholm integral equations of the second kind. The novel error analysis uses an asymptotic approach, in the small parameter of the numerical mesh size, applied to a finite-rank degenerate-kernel orthogonalpolynomial approximation of the exact kernel. It is proved that, under suitable conditions, the discrepancy between our theoretically predicted error and the actual numerical error tends to zero at the rate ‖K − KM‖, where M is the rank of the degenerate-kernel approximation. A leading-order error analysis is validated on three increasingly accurate projection methods applied to both smooth and sharply peaked kernels, our error predictions being demonstrated to be exponentially convergent to experimentally obtained global numerical errors. The new method is demonstrated to be cost-effective relative to standard extrapolation.
Characterizing user behavior in online social networks

Understanding how users behave when they connect to social networking sites creates opportunities for better interface design, richer studies of social interactions, and improved design of content distribution systems. In this paper, we present a first of a kind analysis of user workloads in online social networks. Our study is based on detailed clickstream data, collected over a 12-day period, summarizing HTTP sessions of 37,024 users who accessed four popular social networks: Orkut, MySpace, Hi5, and LinkedIn. The data were collected from a social network aggregator website in Brazil, which enables users to connect to multiple social networks with a single authentication. Our analysis of the clickstream data reveals key features of the social network workloads, such as how frequently people connect to social networks and for how long, as well as the types and sequences of activities that users conduct on these sites. Additionally, we crawled the social network topology of Orkut, so that we could analyze user interaction data in light of the social graph. Our data analysis suggests insights into how users interact with friends in Orkut, such as how frequently users visit their friends' or non-immediate friends' pages. In summary, our analysis demonstrates the power of using clickstream data in identifying patterns in social network workloads and social interactions. Our analysis shows that browsing, which cannot be inferred from crawling publicly available data, accounts for 92% of all user activities. Consequently, compared to using only crawled data, considering silent interactions like browsing friends' pages increases the measured level of interaction among users.
Annealing-induced Changes in the Electronic and Structural Properties of ZnTe Substrates

The aim of this study is to demonstrate that the electronic and structural properties of II–VI substrates, here ZnTe, can be dramatically affected by thermal heating at temperatures in the range of those typically used in the epitaxial metalorganic chemical vapor deposition processes. Photoluminescence response shows that annealing at these temperatures produces a reduction of the sample crystalline quality, decreasing the free exciton emission relative to the deep level related one. Some factors, like the change in the charge and stress state of dislocations, Cu diffusion, and oxygen incorporation, could be responsible for changes in the substrate properties, which can produce stresses and contamination in the deposited sample.