Miracle-dz/UniFAR-FTUs huggingface dataset:
Building a Social Network One Choice at a Time

Newcomers to a social network show preferential attachment, a tendency to befriend those with many friends. Here, we show that preferential attachment is equivalent to a form of ‘probability matching’ commonly found in studies of decision-making. This equivalence, whereby newcomers probability match to a social signal akin to popularity, marries network science to the study of decision-making and raises new questions about how individual psychology impacts the social structure of groups. We asked people to view a visualization of a social network and to select group members whom they would like to meet and befriend. People varied in how strongly they weighed popularity and this was mildly correlated with aspects of their personality. Individual differences in preferential attachment affect the structure and connectivity of the network that emerges.
Optimal Strategies for Cooperative MAC-Layer Retransmission in Wireless Networks

The concept of cooperative retransmission in wireless networks has attracted considerable research attention. The basic idea is that when a receiver cannot decode a frame, the retransmission is handled not by its original source but rather by a neighbour that overheard the transmission successfully, and may have a better channel to the destination. However, the majority of existing literature tackles the issue from the physical layer perspective, with either a single cooperating neighbour, or a multiple-neighbour setting where the receiver is capable of combining and decoding the signal from several simultaneous retransmissions. In this paper, we consider the case of multiple cooperating neighbours from a MAC-layer perspective. Thus, we assume a receiver that can only decode one transmission at a time, while multiple simultaneous retransmissions (by several neighbours that had overheard the frame successfully) will cause a collision. As a result, each neighbour with a successfully overheard copy of the frame faces a tradeoff between helping with a cooperative retransmission and possibly causing a collision. Accordingly, we pose the optimization problem of finding a distributed randomized strategy for the cooperating neighbours, which assigns a certain retransmission probability to every neighbour in each time slot, so as to minimize the expected latency until successful reception. We analyse the performance achieved by two approaches: one where the original source is silent while the neighbours conduct their cooperative retransmissions, and another where both the source and the neighbours may have a nonzero retransmission probability simultaneously. We show that the latter approach offers a significant performance improvement over the former one, as well as either traditional retransmission or two-hop routing to the destination.
The costs and limits of availability for replicated services

As raw system and network performance continues to improve at exponential rates, the utility of many services is increasingly limited by availability rather than performance. A key approach to improving availability involves replicating the service across multiple, wide-area sites. However, replication introduces well-known tradeoffs between service consistency and availability. Thus, this paper explores the benefits of dynamically trading consistency for availability using a continuous consistency model. In this model, applications specify a maximum deviation from strong consistency on a per-replica basis. In this paper, we: i) evaluate availability of a prototype replication system running across the Internet as a function of consistency level, consistency protocol, and failure characteristics, ii) demonstrate that simple optimizations to existing consistency protocols result in significant availability improvements (more than an order of magnitude in some scenarios), iii) use our experience with these optimizations to prove tight upper bounds on the availability of services, and iv) show that maximizing availability typically entails remaining as close to strong consistency as possible during times of good connectivity, resulting in a communication versus availability trade-off.
Enhancements in wireless broadband networks using Smart Caching An analytical evaluation

Since ubiquitous mobile communication is already true in many countries in the future the provisioning of broadband access for mobile users is the key functionality. For mobile users the performance of the radio network vitally depends on the length and the characteristic of the transmission path between user terminal and access point. Due to the continuously changing conditions the link quality will be subject to high variations which make especially broadband services hard to realize. In urban environments a full broadband coverage is therefore hard to provide. In the following the Smart Caching technology is presented which allows the overcoming of these problems at least for non- real-time and non-interactive services. It uses the approach of pre-fetching and buffering data at the edge of the core network and transmitting it whenever the user gets connected to an access node with broadband connectivity. The paper provides a detailed description of Smart Caching and an analytical evaluation of the advantages of Smart Caching enabled networks compared to legacy setups. Furthermore dimensioning issues are covered. For the analysis advanced queuing theory is used. User services are modeled in very detail as well as radio link, network and user behavior.
Smart card based secure authentication and key agreement protocol

In 2005, Yoon-Ryu-Yoo proposed a simple remote user authentication scheme which is an improvement on Hwang-Lee-Tang's scheme. However, we found that Yoon-Ryu-Yoo's scheme easily reveals a user's password and is vulnerable to impersonation attack using stolen smart card. This scheme is also found to be vulnerable to parallel session attack and man-in-the-middle attack. This paper proposes a new remote user authentication scheme that resolves the aforementioned problems, while keeping the merits of Yoon-Ryu-Yoo's scheme.
Assessing compliance: Active versus inactive trainees in a memory intervention

Extensive research on memory interventions has confirmed their success with older adults, but the individual difference factors that predict successful training outcomes remain relatively unexplored. In the current intervention, trainees were identified as active (compliant with training regimens) or inactive using trainer ratings based on attendance, homework completion, and class participation. The active group showed significantly greater training-related gains than the inactive group and the control group on most measures. Compliance was predicted by health, education, and self-efficacy. Specifically, active trainees were more likely to have advanced degrees and somewhat higher self-efficacy, and to have higher vitality and fewer functional limitations than the inactive trainees. This research may assist future investigators to target interventions to those who will show the most benefit.
The temporal dynamics of strategy execution in cognitive skill learning

The transition from algorithmic to memory-based performance is a core component of cognitive skill learning. There has been debate about the temporal dynamics of strategy execution, with some models assuming a race (i.e., independent, capacity unconstrained parallel processing) between algorithm and retrieval, and others assuming a choice mechanism. The authors investigated this issue using a new approach that allows the latency of each algorithm step to be measured, in turn providing new insight into (a) whether there is slowing of 1 or more algorithm steps on trials immediately preceding the 1st retrieval trial for an item, as might be expected if there is a competitive strategy execution process of some type other than a race, and (b) whether there is partial algorithm completion on retrieval trials, as would be expected if the 2 strategies are executed in parallel. Results are uniquely consistent with a strategy choice mechanism involving a competition between the retrieval strategy and the 1st step of the algorithm.
The Distribution of Pseudoprimes

The RSA crypto-system relies on the availability of very large prime numbers. Tests for finding these large primes can be categorized as deterministic and probabilistic. Deterministic tests, such as the Sieve of Erastothenes, offer a 100 percent assurance that the number tested and passed as prime is actually prime. Despite their refusal to err, deterministic tests are generally not used to find large primes because they are very slow (with the exception of a recently discovered polynomial time algorithm). Probabilistic tests offer a much quicker way to find large primes with only a negligibal amount of error. I have studied a simple, and comparatively to other probabilistic tests, error prone test based on Fermat’s little theorem. Fermat’s little theorem states that if b is a natural number and n a prime then b ≡ 1 (mod n). To test a number n for primality we pick any natural number less than n and greater than 1 and first see if it is relatively prime to n. If it is, then we use this number as a base b and see if Fermat’s little theorem holds for n and b. If the theorem doesn’t hold, then we know that n is not prime. If the theorem does hold then we can accept n as prime right now, leaving a large chance that we have made an error, or we can test again with a different base. Chances improve that n is prime with every base that passes but for really big numbers it is cumbersome to test all possible bases. A number that passes the aforementioned test for an arbitrary base b but is composite is called a pseudoprime base b. I have studied pseudoprimes base 2, which I will henceforth just call pseudoprimes. I have also investigated a family of pseudoprimes called Carmichael numbers, which are pseudoprime with all bases relatively prime. Knowing of the prime number theorem (not necesarrily understanding), and the great interest in the distribution of prime numbers, I naturally became curious as to whether there was any theorem describing the distribution of pseudoprimes or Carmichael numbers. It seemed to be a good research opportunity and so I began by writing some programs in the Java programming language to count pseudoprimes. I
Pursuit of intermittently illuminated moving targets in the human.

1. Experiments have been conducted in order to establish the changes in oculomotor activity which take place when the human subject attempts to pursue an intermittently illuminated moving target. 2. In an initial experiment, target motion in the horizontal plane was composed of one or two sinusoids at frequencies between 0.11 and 0.2 Hz. The target was illuminated for varying durations (10‐320 ms) at intervals between 40 and 960 ms. As pulse interval was increased or pulse duration was decreased there was a progressive increase in eye velocity gain for the smooth component of eye movement. Some smooth eye movement was generated even when the pulse interval was as large as 960 ms. 3. In a second experiment target motion consisted of a triangular waveform in which target presentation was timed to occur at regular intervals throughout each cycle. Overlaying and averaging the response from several cycles revealed a regular pattern of pulsatile activity associated with each target presentation. This response, which was particularly evident when the pulse interval was greater than 1 s, consisted of an initial build‐up of smooth eye velocity followed by an exponential decay with a time constant of 0.5‐2 s. When the pulse interval was less than 1 s there was a summation of the transient responses so that eye movement appeared quite smooth when pulse interval was reduced to 320 ms. 4. The pulsatile nature of the response was accentuated when the target was made to execute a staircase‐ramp waveform in which the target was illuminated only during the ramp component. The elimination of position change between ramps and the ability to achieve higher target velocity led to clear evidence of the summation of transient oculomotor responses. 5. The summated effects, however, were not simply attributable to the addition of responses to individual target presentations as indicated by the timing of each response. The eye velocity pulse was frequently initiated 200‐300 ms prior to target appearance, and well before the time (100 ms) at which visual feedback would be expected to become effective. 6. The effect of target step displacement alone was investigated by examination of the smooth eye movement initiated by varying numbers of steps in the waveform. This showed that the basic step response had a peak velocity of no more than 8‐10 deg/s in most individuals. (ABSTRACT TRUNCATED AT 400 WORDS)
Quad-Based Audio Fingerprinting Robust to Time and Frequency Scaling

We propose a new audio fingerprinting method that adapts findings from the field of blind astrometry to define simple, efficiently representable characteristic feature combinations called quads. Based on these, an audio identification algorithm is described that is robust to large amounts of noise and speed, tempo and pitch-shifting distortions. In addition to reliably identifying audio queries that are modified in this way, it also accurately estimates the scaling factors of the applied time/frequency distortions. We experimentally evaluate the performance of the method for a diverse set of noise, speed and tempo modifications, and identify a number of advantages of the new method over a recently published distortioninvariant audio copy detection algorithm.
DEM Reconstruction in Layover Areas From SAR and Auxiliary Input Data

In this letter, a methodology to overcome the layover problem and obtain the 3-D reconstruction of urban areas will be discussed. Interferometric synthetic aperture radar (SAR) (InSAR) systems allow the estimation of height profiles of the Earth surface, but in the case of urban scenarios, estimation becomes a hard task due to the presence of SAR geometrical distortions, with layover above all. First, the layover signal in InSAR images is investigated; then, a procedure to specifically manage layover areas is presented. The proposed method consists of introducing an auxiliary data exploitation, optical data or SAR shadowing, in the maximum a posteriori statistical estimation technique to improve the digital elevation model reconstruction, particularly on phase discontinuities. We test the method on simulated data, showing its effectiveness.
Climate change and glacier retreat drive shifts in an Antarctic benthic ecosystem

Climatic change in the Antarctic Peninsula has driven profound shifts in the seabed. The Antarctic Peninsula (AP) is one of the three places on Earth that registered the most intense warming in the last 50 years, almost five times the global mean. This warming has strongly affected the cryosphere, causing the largest ice-shelf collapses ever observed and the retreat of 87% of glaciers. Ecosystem responses, although increasingly predicted, have been mainly reported for pelagic systems. However, and despite most Antarctic species being benthic, responses in the Antarctic benthos have been detected in only a few species, and major effects at assemblage level are unknown. This is probably due to the scarcity of baselines against which to assess change. We performed repeat surveys of coastal benthos in 1994, 1998, and 2010, analyzing community structure and environmental variables at King George Island, Antarctica. We report a marked shift in an Antarctic benthic community that can be linked to ongoing climate change. However, rather than temperature as the primary factor, we highlight the resulting increased sediment runoff, triggered by glacier retreat, as the potential causal factor. The sudden shift from a “filter feeders–ascidian domination” to a “mixed assemblage” suggests that thresholds (for example, of tolerable sedimentation) and alternative equilibrium states, depending on the reversibility of the changes, could be possible traits of this ecosystem. Sedimentation processes will be increasing under the current scenario of glacier retreat, and attention needs to be paid to its effects along the AP.
Exposing Digital Forgeries in Ballistic Motion

We describe a geometric technique to detect physically implausible trajectories of objects in video sequences. This technique explicitly models the three-dimensional ballistic motion of objects in free-flight and the two-dimensional projection of the trajectory into the image plane of a static or moving camera. Deviations from this model provide evidence of manipulation. The technique assumes that the object's trajectory is substantially influenced only by gravity, that the image of the object's center of mass can be determined from the images, and requires that any camera motion can be estimated from background elements. The computational requirements of the algorithm are modest, and any detected inconsistencies can be illustrated in an intuitive, geometric fashion. We demonstrate the efficacy of this analysis on videos of our own creation and on videos obtained from video-sharing websites.
Do Children and Adolescents with Anorexia Nervosa Display an Inefficient Cognitive Processing Style?

Objective This study aimed to examine neuropsychological processing in children and adolescents with Anorexia Nervosa (AN). The relationship of clinical and demographic variables to neuropsychological functioning within the AN group was also explored. Method The performance of 41 children and adolescents with a diagnosis of AN were compared to 43 healthy control (HC) participants on a number of neuropsychological measures. Results There were no differences in IQ between AN and HC groups. However, children and adolescents with AN displayed significantly more perseverative errors on the Wisconsin Card Sorting Test, and lower Style and Central Coherence scores on the Rey Osterrieth Complex Figure Test relative to HCs. Conclusion Inefficient cognitive processing in the AN group was independent of clinical and demographic variables, suggesting it might represent an underlying trait for AN. The implications of these findings are discussed.
A survey of assessment center practices in organizations in the United States.

Two hundred fifteen organizations in the United States provided information about multiple aspects of their assessment centers, including design, usage, and their adherence to professional guidelines and research-based suggestions for the use of this method. Results reveal that centers are usually conducted for selection, promotion, and development purposes. Supervisor recommendation plays a sizable role in choosing center participants. Most often, line managers act as assessors; they typically arrive at participant ratings through a consensus process. In general, respondents indicate close adherence to recommendations for center design and assessor training. Recommendations involving other practices (e.g., informing participants, evaluating assessors, validating center results) are frequently not followed. Furthermore, methods thought to improve predictive validity of center ratings are underutilized. Variability in center practices according to industry and center purpose was revealed. We encourage practitioners to follow recommendations for center usage, and researchers to work to better understand moderators of center validity.
Associations between environmental exposures and asthma control and exacerbations in young children: a systematic review

Objective To complete a systematic review of the literature describing associations between all environmental exposures and asthma symptoms and exacerbations in children up to mean age of 9 years. Design Systematic review. Setting Reference lists of identified studies and reviews were searched for all articles published until November 2013 in electronic databases (MEDLINE, EMBASE, CINAHL, Cochrane Controls Trials Register). Participants Studies were selected which examined a link between exposure to environmental factors and asthma symptoms and exacerbations where the study participants were children with a mean age of ⩽9 years. Primary and secondary outcome measures Indices of asthma symptoms, control and exacerbations. Results A total of 27 studies were identified including eight where inhaled allergens and four where environmental tobacco smoke (ETS) were the exposures of interest. There was evidence that exposure to allergen, ETS, poor air quality and unflued heaters had a modest magnitude of effect (ORs between 2 and 3). There was also evidence of interactions observed between exposures such as allergen and ETS. Conclusions Exposure to inhaled allergens, ETS, unflued heaters and poor air quality has an important effect on exacerbations in young children with asthma and should be minimised or, ideally, avoided. Better understanding of the effect of exposure to damp housing, air conditioning and dietary factors plus interactions between environmental exposures associated with exacerbations is required.
Sequential and myopic: On the use of feedback to balance cost and utility in a simulated electricity efficiency task

ABSTRACT While there is extensive research on feedback, little research is aimed at the use of feedback to optimise conflicting goals. A task modelled after In Home Displays for providing feedback about electricity cost was designed to investigate the effects of feedback frequency, detail, and stability, when participants try to balance cost and utility. Frequent feedback proved to be advantageous in a deterministic system, but feedback aggregated over time was advantageous in a system with noisy feedback. Surprisingly, performance was better with noisy feedback, where the probabilism, in effect, acted as a filter, highlighting the applications that are most important for the cost and the utility. Computational modelling suggested that the best-fitting model assumes that the participants are sequential, considering one goal at a time, first satisfying the cost budget, only thereafter trying to maximise the utility, and reflexive, myopically responding primarily to the feedback explicitly available on a given trial.