Miracle-dz/UniFAR-FTUs huggingface dataset:
Modeling social strength in social media community via kernel-based learning

Modeling continuous social strength rather than conventional binary social ties in the social network can lead to a more precise and informative description of social relationship among people. In this paper, we study the problem of social strength modeling (SSM) for the users in a social media community, who are typically associated with diverse form of data. In particular, we take Flickr---the most popular online photo sharing community---as an example, in which users are sharing their experiences through substantial amounts of multimodal contents (e.g., photos, tags, geo-locations, friend lists) and social behaviors (e.g., commenting and joining interest groups). Such heterogeneous data in Flickr bring opportunities yet challenges to the research community for SSM. One of the key issues in SSM is how to effectively explore the heterogeneous data and how to optimally combine them to measure the social strength. In this paper, we present a kernel-based learning to rank framework for inferring the social strength of Flickr users, which involves two learning stages. The first stage employs a kernel target alignment algorithm to integrate the heterogeneous data into a holistic similarity space. With the learned kernel, the second stage rectifies the pair-wise learning to rank approach to estimating the social strength. By learning the social strength graph, we are able to conduct collaborative recommendation and collective classification. The promising results show that the learning-based approach is effective for SSM. Despite being focused on Flickr, our technique can be applied to model social strength of users in any other social media community.
SNR‐dependent radius control sphere detection for MIMO systems and relay networks

A new sphere decoder algorithm for uncoded spatial multiplexing multiple‐input multiple‐output (MIMO) systems is proposed. It overcomes the drawbacks of traditional sphere decoders: variable complexity and high complexity in low signal‐to‐noise ratios (SNRs). Its main novelty lies in scaling the search radius by a heuristic SNR‐dependent factor. This new SNR‐dependent radius control sphere decoder offers near maximum likelihood performance over the entire range of SNRs, while keeping its complexity roughly constant. This algorithm also incorporates channel ordering to save complexity. To quantify the variability of complexity, the normalised variance of the complexity is evaluated. This algorithm is also extended for joint iterative detection and decoding in coded MIMO systems and for MIMO‐relay networks. Simulation results and theoretical analysis demonstrate the benefits of the proposed algorithm.Copyright © 2013 John Wiley & Sons, Ltd.
Betaine alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet

To assess the effects of betaine on hepatic lipid accumulation and investigate the underlying mechanism, thirty-two male Sprague–Dawley rats weighing 100 (sd 2·50) g were divided into four groups, and started on one of four treatments: basal diet, basal diet with betaine administration, high-fat diet and high-fat diet with betaine administration. The results showed that no significant difference of body weight was found among experimental groups. Compared with high-fat diet-fed rats, a betaine supplementation decreased (P< 0·05) hepatic TAG accumulation induced by high-fat diet, which was also supported by hepatic histology results. Additionally, hepatic betaine–homocysteine methyltransferase activity as well as its mRNA abundance and lecithin level were found increased (P< 0·05) by betaine supplementation in both basal diet-fed rats and high-fat diet-fed rats. Betaine administration in high-fat diet-fed rats exhibited a higher (P< 0·05) activity of hepatic carnitine palmitoyltransferase 1 (CPT1) compared with high-fat diet-fed rats. High-fat diet inhibited (P< 0·05) the gene expression of hepatic PPARα and CPT1. However, betaine administration in high-fat diet-fed rats elevated (P< 0·05) the gene expression of PPARα and CPT1. Moreover, concentration, gene and protein expressions of hepatic fibroblast growth factor 21 (FGF21) were increased (P< 0·05) in response to betaine administration in high-fat diet group; meanwhile the gene expression of hepatic AMP-activated protein kinase was increased (P< 0·05) as well. The results suggest that betaine administration enhanced hepatic lipid export and fatty acid oxidation in high-fat diet-fed rats, thus effectively alleviating fat accumulation in the liver.
ATTITUDES TOWARDS MATHEMATICS , SELF-EFFICACY AND ACHIEVEMENT IN PROBLEM -

The aim of this study was to explore relationships between students’ attitudes towards Mathematics, self-efficacy beliefs in problem-solving and achievement. The possibility of attitudes and selfefficacy to predict problem-solving performance was also examined. Attitude and efficacy scales were completed by 238 fifth-grade pupils. Problem-solving performance was measured by a specially prepared test, including simple and multi-step problems. The analysis of the data indicated significant relationship between attitudes and achievement and a stronger relationship between efficacy and achievement. Attitudes and efficacy were also correlated and both predicted achievement in problem-solving. However, efficacy was a more powerful predictor than attitudes. No gender difference was found in any of the examined variables.
Distributed image processing on spiral architecture

Improving computation efficiency is a key issue in image processing, especially in edge detection, which is very computationally intensive. With the development of real-time applications of image processing, fast processing response is becoming more critical. In this paper, a technique for distributed image processing on a spiral architecture is proposed, which provides a platform for speeding up image processing based on clusters.
In vitro characterization of representative clinical South African Staphylococcus aureus isolates from various clonal lineages

Data concerning the virulence and pathogenesis of South African strains of Staphylococcus aureus are limited. We investigated host–pathogen interactions of randomly selected clinical S. aureus isolates representing various clones. We characterized the ability of isolates to adhere to fibronectin, fibrinogen, collagens IV and VI, to invade host cells and to induce cell death in vitro. We analysed the possible association of these results with characteristics such as methicillin resistance, Panton–Valentine leucocidin (PVL) positivity and clonality. The S. aureus isolates displayed diversity in their abilities to adhere to various human ligands. All isolates were highly invasive except for ST121. PVL-negative isolates were significantly more invasive than the PVL-positive isolates (p 0.004). Isolates of CC5, CC30 and CC121 were non-cytotoxic, whereas isolates of CC22, CC8, CC15, CC45 and CC88 were very cytotoxic. No statistical association was identified between cell death and methicillin resistance, bacterial PVL status, clonality or patient HIV status. The vast majority of isolates were invasive and induced significant cell death. PVL-negative isolates were more invasive than PVL-positive isolates, while methicillin-resistant isolates were not found to be more invasive or cytotoxic than methicillin-susceptible isolates.
The Impact of Healthscape on Customer Satisfaction and Loyalty in Public and Private Healthcare Institutions

The evaluation of services is highly dependable on consumers’ experiences and emotions toward the service encounter. The service environment (the servicescape) has an influential aspect on customers’ satisfaction and behavioral intentions including customer loyalty. This study aims to define the possible effects of the healthcare service environment (healthscape) on consumer experience, satisfaction and loyalty. The data was collected from patients that has visited an outpatient clinic, ER, laboratory or had an operation from a private or public hospital within the last 30 days. A questionnaire was administrated to collect data on helathscape perceptions, emotional responses toward the healthscape, customer satisfaction, and customer loyalty including both re-purchase and WOM intentions. The study has yielded that the physical dimension of the healthscape to be the most influential antecedent of consumers’ emotional responses.
Hard Lefschetz Theorem for Valuations, Complex Integral Geometry, and Unitarily Invariant Valuations

We obtain new general results on the structure of the space of translation invariant continuous valuations on convex sets (a version of the hard Lefschetz theorem). Using these and our previous results we obtain explicit characterization of unitarily invariant translation invariant continuous valuations. It implies new integral geometric formulas for real submanifolds in Hermitian spaces generalizing the classical kinematic formulas in Euclidean
Determinants of Premiums on Self-Tender Offers

We investigate why firms pay a premium when making a tender offer to repurchase shares, and if the size of the premium is related to the elasticity of the supply curve for the firm's stock. We find that premiums on self-tender offers are related to characteristics of tendering firms, and to variables that are proxies both for the capital gains and for the information content of the announcement. Our results indicate that stock price inelasticity, caused by taxes, is an important determinant of offer premiums for fixed-price self-tender offers. We also find that the information conveyed by the offer, measured by the post-expiration appreciation of the firm's stock, is contained in the tender offer premium, and that offer premiums are inversely related to firm size and to preoffer stock performance. In addition, we present evidence that share repurchase tender offers may frequently be oversubscribed by design.
Projective Modules over Higher-Dimensional Non-Commutative Tori

The non-commutative tori provide probably the most accessible interesting examples of non-commutative differentiable manifolds. We can identify an ordinary n-torus Tn with its algebra, C(Tn), of continuous complex-valued functions under pointwise multiplication. But C(Tn) is the universal C*-algebra generated by n commuting unitary operators. By definition, [15, 16, 50], a non-commutative n-torus is the universal C*-algebra generated by n unitary operators which, while they need not commute, have as multiplicative commutators various fixed scalar multiples of the identity operator. As Connes has shown [8, 10], these algebras have a natural differentiable structure, defined by a natural ergodic action of Tn as a group of automorphisms. The non-commutative tori behave in inany ways like ordinary tori. For instance, it is an almost immediate consequence of the work of Pimsner and Voiculescu [37] that the K-groups of a non-commutative torus are the same as those of an ordinary torus of the same dimension. (In particular, non-commutative tori are KK-equivalent to ordinary tori by Corollary 7.5 of [52].) Furthermore, the structure constants of non-commutative tori can be continuously deformed into those for ordinary tori. (This is exploited in [17].)
Prevalence of and Factors Influencing Parent–Child Communication About HIV/AIDS, and Sexual and Reproductive Health Issues in Nigeria

This study investigated the prevalence of and factors that determine parent–child communication about HIV/AIDS and sexual and reproductive health (SRH) issues in Nigeria. The study used data from the National HIV/AIDS and Reproductive Health Survey (NARHS). The data are nationally representative and offers sociodemographic information on women aged 15 to 49 years and men aged 15 to 64 years. Prevalence of parent–child communication about HIV/AIDS, family planning, and contraception was generally low at 37.4%, 32.5%, and 9.5%, respectively. Determinants of discussions with children on HIV/AIDS, family planning, and contraception were respondents’ zone, economic status, and educational attainment. Parents held more discussions with female children than with the males. Parents aged 50 to 64 years, compared with the younger parents, were double likely (odds ratio [OR] = 2.04; 1.52-2.73) to discuss HIV/AIDS with their wards older than 13 years. Male parents, parents living in urban areas, and parents with richer economic status had higher odds of discussing HIV/AIDS and SRH issues with their wards.
COORDINATED INVENTORY PLANNING FOR NEW AND OLD PRODUCTS UNDER WARRANTY

In this article we study a firm that is facing demand from two sources: demand for new items and demand to replace failed items under warranty. We model this setting as a multiperiod single-product inventory problem where the demands for new items in different periods are independent and the demands for replacing failed items depend on the number of the items under warranty. We consider backlogging and emergency supply cases and study both discounted-cost and average-cost criteria. We prove the optimality of the w-dependent base stock ordering policy, where the base stock level is a function of w, the number of items currently under warranty. For the special case where the demand for new products is stationary, we prove the optimality of a stationary w-dependent base stock policy for the finite-horizon discounted-cost and the infinite-horizon discounted- and average-cost cases. We compare the integrated inventory policy with the one that neglects demands from items under warranty.
Learning Through Assessment : OLAL . . On-Line Assessment and Learning

This paper describes the development of a multiple choice, computerised, and formative On Line Assessment & Learning System (OLAL), and the results and feedback with respect to the system's introduction into a degree module as a means of assessment, and as a tool to facilitate learning. This system was developed to replace the current exam based process as a means of assessing a level two degree module in Computer Communications and Networks within the School of Computing at the University of Glamorgan. The OLAL system, significantly reduces the marking load on the academic member of staff, but at the same time clearly addresses the issues of instantaneous student feedback, and the maintaining of standards within the subject area without the final examination process being undertaken. It allows the assessment of the student's understanding of the subject area, rather than merely addressing their ability in report writing or proficiency in the use of a specific development tool. The use of OLAL, permits the cumulative assessment of the students at four stages throughout the module. The students, whilst performing the test, are permitted two attempts, with the same questions being presented on each occasion. The cumulative score of these passes, in the ratio of 60/40, is then stored away to the student database for assessment purposes. The test includes a timer per question, ensuring that the students are in a "pressure environment" whilst performing the test. It also allows the student time to make use of the formative nature of the system in checking whether they were correct, or if not, then why? The marking scheme of the system includes a score of plus two for a correct solution and a punitive measure of minus one for an incorrect solution. This simplistic measure of allowing two attempts of the test provides a very effective learning mechanism, rather than a pure assessment exercise, as is the normal situation in the standard non-formative examination process. The test also provides a valuable tool in automatically reporting on questions which have caused problems to the students, and hence suggests areas of questioning to be passed through to the next stages of assessment, and also indicates areas of the course which may require further lecturing or directed support. The paper analyses the overall results produced by the introduction of this system with respect to the students' perceived understanding of the subject area. It also addresses the efficiency of the system, and also reports upon the student feedback concerning their acceptance of the system as both a means of assessment and its formative and learning features.
The Aiding of MEMS INS/GPS Integration Using Artificial Intelligence for Land Vehicle Navigation

This paper applies two Artificial Intelligence (AI) techniques, fuzzy logic and expert system, to enhance the Kalman filter-based MEMS INS/GPS integration. For better INS error control, the expert knowledge on vehicle dynamics is utilized to simplify dynamics models and to extend measurement update schemes in the velocity filter. To optimize position fusion, a fuzzy inference system is developed to provide GPS signal degradation information for modification of the innovation-based adaptive measurement covariance in the position filter. The effectiveness of the proposed AI-based enhancement methods is demonstrated through several field tests.
Modulation of Risky Choices in Recently Abstinent Dependent Cocaine Users: A Transcranial Direct-Current Stimulation Study

Previous neurobiological and neuropsychological investigations have shown that risk-taking behaviors and addictions share many structural and functional aspects. In particular, both are characterized by an irresistible need to obtain immediate rewards and by specific alterations in brain circuits responsible for such behaviors. In this study, we used transcranial direct-current stimulation over the dorsolateral prefrontal cortex (DLPFC) of two samples of subjects (18 dependent cocaine users and 18 control subjects) to investigate the effects of left and right cortical excitability on two risk tasks: (1) the balloon analog risk task (BART) and (2) the game of dice task (GDT). All subjects randomly received a left anodal/right cathodal stimulation (LAn+), a right anodal/left cathodal stimulation (RAn+), and a sham (placebo) stimulation each run at least 48 h apart. Participants were asked to perform the BART and the GDT immediately before and after each stimulation. Our results reveal that the activation of the DLPFC (left and right) results in a reduction of risky behaviors at the BART task both in controls subjects and cocaine dependent users. The effect of tDCS on GDT, instead, is more complex. Cocaine users increased safe behavior after right DLPFC anodal stimulation, while risk-taking behavior increased after left DLPFC anodal stimulation. Control subjects’ performance was only affected by the anodal stimulation of the right DLPFC, resulting in an increase of safe bets. These results support the hypothesis that excessive risk propensity in dependent cocaine users might be due to a hypoactivation of the right DLPFC and an unbalance interhemispheric interaction. In conclusion, since risky decision-making seems to be, at least in part, responsible for maintenance and relapse of addiction, we argue that a neuromodulation-based approach could represent a valuable adjunct in the clinical treatment of addiction.
Game-based Assessment of Psycho-acoustic Thresholds: Not All Games Are Equal!

This paper first presents a critical analysis of an existing game (APEX), designed by researchers in psychoacoustics only, to measure psychoacoustic thresholds in preschoolers. Next it presents another game (DIESEL-X), designed by dyslexia researchers and game designers, to remediate the shortcomings of the former game. Via a repeated measures experiment (n = 95), the game experience, attention, and psychoacoustic thresholds are compared. It is shown that the children prefer the game experience of DIESEL-X over APEX. Moreover, the former game was able to measure lower frequency-modulation thresholds than APEX. These results demonstrate that when it comes down to game-based assessment of children's perceptual capabilities, the quality of game design not only has an effect on game experience, but equally on the scientific measurements obtained via such a game-based assessment.
Revenue-maximizing and truthful online auctions for dynamic spectrum access

Secondary spectrum auctions have been suggested as a strategically robust mechanism for distributing idle spectrum to competing secondary users. However, previous work on such auction design have assumed a static auction setting, thus failing to fully exploit the inherently time-varying nature of spectrum demand and utilization. In this paper, we address this issue from the perspective of the primary user who wishes to maximize the auction revenue. We present an online auction framework that dynamically accepts bids and allocates spectrum. We prove rigorously that our online auction framework is truthful in the multiple dimensions of bid values, as well as bid timing parameters. To protect against unbounded loss of revenue due to latter bids, we introduce controlled preemption into our mechanism. We prove that preemption, coupled with the technique of inflating bids artificially, leads to an online auction that guarantees a 1/5-fraction of the optimal revenue as obtained by an offline adversary. Since the previous guarantee holds only for the optimal channel allocation, we further provide a greedy channel allocation scheme which provides scalability. We prove that the greedy scheme also obtains a constant competitive revenue guarantee, where the constant depends on the parameter of the conflict graph.
Effectivness of abstract interpretation in automatic parallelization: a case study in logic programming

We report on a detailed study of the application and effectiveness of program analysis based on abstract interpretation of automatic program parallelization. We study the case of parallelizing logic programs using the notion of strict independence. We first propose and prove correct a methodology for the application in the parallelization task of the information inferred by abstract interpretation, using a parametric domain. The methodology is generic in the sense of allowing the use of different analysis domains. A number of well-known approximation domains are then studied and the transformation into the parametric domain defined. The transformation directly illustrates the revelance and applicability of each abstract domain for the application. Both local and global analyzers are then built using these domains and embedded in a complete parallelizing compiler. Then, the performance of the domains in this context is assessed through a number of experiments. A comparatively wide range of aspects is studied, from the resources needed by the analyzers in terms of time and memory to the actual benefits obtained from the information inferred. Such benefits are evaluated both in terms of the characteristics of the parallelized code and of the actual speedups obtained from it. The results show that data flow analysis plays an important role in achieving efficient parallelizations, and that the cost of such analysis con be reasonable even for quite sophisticated abstract domains. Furthermore, the results also offer significant insight into the characteristics of the domains, the demands of the application, and the trade-offs involved.