Can the Web turn into a digital library?

There is no doubt that the enormous amounts of information on the WWW are influencing how we work, live, learn and think. However, information on the WWW is in general too chaotic, not reliable enough and specific material often too difficult to locate that it cannot be considered a serious digital library. In this paper we concentrate on the question how we can retrieve reliable information from the Web, a task that is fraught with problems, but essential if the WWW is supposed to be used as serious digital library. It turns out that the use of search engines has many dangers. We will point out some of the possible ways how those dangers can be reduced and how dangerous traps can be avoided. Another approach to find useful information on the Web is to use “classical” resources of information like specialized dictionaries, lexica or encyclopaedias in electronic form, such as the Britannica. Although it seemed for a while that such resources might more or less disappear from the Web due to attempts such as Wikipedia, some to the classical encyclopaedias and specialized offerings have picked up steam again and should not be ignored. They do sometimes suffer from what we will call the “wishy-washy” syndrome explained in this paper. It is interesting to note that Wikipedia which is also larger than all other encyclopaedias (at least the English version) is less afflicted by this syndrome, yet has some other serious drawbacks. We discuss how those could be avoided and present a system that is halfway between prototype and production system that does take care of many of the aforementioned problems and hence may be a model for further undertakings in turning (part of) the Web into a useable digital library.     

An Online Algorithm for a Problem in Scheduling with?Set-ups?and Release Times

We address the problem of sequential single machine scheduling of jobs with release times, where jobs are classified into types, and the machine must be properly configured to handle jobs of a given type. The objective is to minimize the maximum flow time (time from release until completion) of any job. We consider this problem under the assumptions of sequence independent set-up times and item availability with the objective of minimizing the maximum flow time. We present an online algorithm that is O(1)-competitive, that is, always gets within a constant factor of optimal. We also show that exact offline optimization of maximum flow time is NP-hard.     

Electrokinetic transport in a water–chloride nanofilm in contact with a silica surface with discontinuous charged patches

This paper reports on simulations of electrokinetic transport in an electrolyte nanofilm in contact with a negatively charged substrate with discontinuous counter-charged patches. All-atom molecular dynamics simulations of an aqueous solution of chloride placed on a silica slab were conducted. The response of the system is investigated as it is subjected to different axial electric fields and as the surface electrostatics is modified by implementing different positive charge densities on the patches. Chloride and water density profiles reveal that the charged patches cause an enrichment of hydrated chloride ions near the surface. Therefore, the system with patches proved to be successful in trapping ions. Moreover, the number of chloride ions trapped on the surface increases as higher charge densities are imposed on the patches. It is observed that higher axial electric fields remove chloride ions from the surface; however, the amount removed decreases as higher charge densities are imposed on the patches. Velocity profiles show a stagnant water layer near the patches. The water and ion accumulation suggest the formation of a Stern layer with thickness of ca. 0.4?nm on the patches. Higher chloride density near the surface and increased surface-water affinity induced by the presence of charged patches result in smaller electroosmotic velocities. The simulation results compare well with velocities calculated using a continuum approach. This study shows that in a charged electrolyte solution in contact with a substrate, axial and normal ion distributions and consequently electroosmotic velocities can be controlled by modifying the electrostatics of the substrate.     

Can a robot empathize with people?

This article explores a robotogenetic model of empathetic understanding of another mind as one of the capabilities required in human–robot social interactions. The term robotogenetic means that we implement a possible ontogeny (i.e., developmental process) of the social capability onto a robotic embodiment with a certain phylogenetic background (i.e., innate prerequisites). First, we look into infants development of social and communicative skills, especially of empathetic understanding of others. We then consider two fundamental abilities, namely eye-contact and joint attention, as the prerequisites for this cognitive development. Then in psychological experiments using robots that are capable of eye-contact and joint attention, we observe how people, especially infants and children, attribute mental states to the robots. Based on these investigations, we consider a possible mechanism of empathy which is based on the spatiotemporal coordination of attention and bodily movement between the self and another.This work was presented in part at the 8th International Symposium on Artificial Life and Robotics, Oita, Japan, January 24–26, 2003     

What holds in a context?

In order to establish that [A] = [B] follows from a set of assumptions often one provesA =B and then invokes the principle of substitution of equals for equals. It has been observed that in the ancillary proof ofA =B one is allowed to use, in addition to those assumptions of which are free for , certain (open) sentencesP which may not be part of and may not follow from , but are related to the context . We show that in an appropriate formal system there is a closed form solution to the problem of determining precisely what sentencesP can be used. We say that those sentenceshold in the context under the set of assumptions . We suggest how the solution could be exploited in an interactive theorem prover.     

How safe is cycling with a schoolbag?

This study was undertaken as a preliminary investigation to compare cycling errors and sudden stopping distance in secondary students traversing an obstacle course on their bicycle with and without a schoolbag, to determine if further studies of cycling accident aetiology amongst children were warranted. Twenty children cycled as fast as they could around an obstacle course. Each child undertook two separate trials, about an hour apart on a morning of the same day. The children traversed the course one at a time in turn using their own bicycle and wearing their own usual school clothes. For the first trial they did not carry a schoolbag. On the second trial they carried a schoolbag weighing 6 kg. There were no significant differences in the number of cycling errors made by the children when traversing the obstacle course with and without a schoolbag. However, the children generally took longer to complete the course when carrying the schoolbag and stopping distances were greater. It was not possible to be certain that these findings were genuine or whether the effect of carrying the schoolbag was reduced by increased familiarity with the course, since all of the children first traversed the course without a schoolbag and then with one. It is concluded that there is some justification for conducting further studies to explore the implications of carrying schoolbags on cycling accident aetiology amongst children.     

How safe is cycling with a schoolbag?

This study was undertaken as a preliminary investigation to compare cycling errors and sudden stopping distance in secondary students traversing an obstacle course on their bicycle with and without a schoolbag, to determine if further studies of cycling accident aetiology amongst children were warranted. Twenty children cycled as fast as they could around an obstacle course. Each child undertook two separate trials, about an hour apart on a morning of the same day. The children traversed the course one at a time in turn using their own bicycle and wearing their own usual school clothes. For the first trial they did not carry a schoolbag. On the second trial they carried a schoolbag weighing 6 kg. There were no significant differences in the number of cycling errors made by the children when traversing the obstacle course with and without a schoolbag. However, the children generally took longer to complete the course when carrying the schoolbag and stopping distances were greater. It was not possible to be certain that these findings were genuine or whether the effect of carrying the schoolbag was reduced by increased familiarity with the course, since all of the children first traversed the course without a schoolbag and then with one. It is concluded that there is some justification for conducting further studies to explore the implications of carrying schoolbags on cycling accident aetiology amongst children.     

Is GRP78/BiP a potential salivary biomarker in patients with rheumatoid arthritis?

Purpose : In the last few years, serum and joint synovial fluid have been extensively analyzed for the proteomic research of rheumatoid arthritis (RA) biomarkers. Nonetheless, to date, there have been no studies investigating salivary biomarkers in this condition. Therefore, aim of this study is to investigate the presence of potential biomarkers of RA in human whole saliva. Experimental design : We combined 2‐DE and MS to analyze the whole saliva protein profile of 20 RA patients in comparison with 20 sex‐ and age‐matched healthy subjects. Results : Eight salivary proteins resulted differentially expressed, namely calgranulin A, calgranulin B, apolipoprotein A‐1, 6‐phosphogluconate dehydrogenase, peroxiredoxin 5, epidermal fatty acid‐binding protein, 78 kDa glucose‐regulated protein precursor (GRP78/BiP), and 14‐3‐3 proteins. It is particularly interesting that chaperone GRP78/BiP showed the greatest increase in RA patients. This finding was validated by Western Blot analysis and the over‐expression of GRP78/BiP appear to be distinctive of RA and drugs treatment independent. Conclusions and clinical relevance : This study provides a rationale for further studies aimed at evaluating any correlation between GRP78/BiP and different clinical/serological aspects of the disease in order to improve the diagnostic algorithms of RA.     

Is the cutoff radius in DPD simulations with a fluid of constant density arbitrary?

The DPD (Dissipative Particle Dynamics) method was used to simulate the flow of a fluid occupying the space inside a rotating infinite long cylinder. The fluid was initially at rest and rigid body rotation was expected to be reached. However, as the simulation proceeded, the DP?s (Dissipative Particles) began accumulating near the wall, leaving the cylinder?s core empty of DP?s, obviously, an aphysical solution. To solve this problem it was suggested to set the cutoff radius as a function of the DP?s number density. A conceptual explanation is suggested.     

How should a seated workplace with a tiltable chair be adjusted?

For a tiltable office chair, subjective height preferences may be different to those for conventional fixed-seat chairs, due to altered biomechanics. These preferences, with a tiltable chair and associated table, have been investigated with a total of 108 subjects. To determine the shortest possible way to obtain reliable height measurements, a study (n = 10) was undertaken. It was demonstrated that two days of measurement seem necessary, the first day involving both a too-high and a too-low start position, the second day only a too-high one. Preferences were measured for each of four groups, one (n = 21) accustomed to and another (n = 35) unaccustomed to a tiltable seat; a third (n = 23) was composed of children and the fourth group (n = 19) was making large-scale drawings. When accustomed to the seat, the subjects preferred a greater seat height. The children's seat-height preference was relatively equal to that of adults, whereas their preferred relative table height was greater, most evidently so with decreasing age. The greatest relative seat height was preferred in connection with large-scale drawings. For desk work it is recommended that the seat height should be approximately 3-5 cm above popliteal height, including shoe heels, and the table height 4-6 cm above the actual elbow height.     

Are digital natives a world-wide phenomenon? An investigation into South African first year students’ use and experience with technology

In 2001 Marc Prensky coined the phrase ‘digital natives’ to refer to the new generation of students who have grown up surrounded by technology. His companion papers spurred large amounts of research, debating changes that are required to curricula and pedagogical models to cater for the changes in the student population. This article reports on a study conducted in 2009 of more than 290 first year students at two South African universities. In this study, students were asked about their access to and use of technology. The results portrayed a heterogeneous student population, with varying levels of access to and use of most technologies. One of Prensky’s key features of a digital native is their excitement with Web 2.0 based technologies. Participants in this study however, appear not to use such technologies, and to not be interested in using them in their studies. One tool that students had high levels of access to (98.1%), and use of is the mobile phone. Out of all uses of technology surveyed, tasks involving the mobile phone were ranked in the top two positions. Also when asked to rank different uses of technology particularly for their studies, three of the top five uses relied on a mobile phone.     

Living in a bubble? Toward a unified bubble theory

We generalise the notion of a bubble beyond the financial domain, by showing how a single social mechanism, based on an information feedback-loop, explains both financial bubbles and other seemingly disparate social phenomena, such as the recognition of academic articles, website popularity, and the spread of rumours.

We discuss examples of phenomena explained by this bubble mechanism, as well as other phenomena that exhibit certain bubble characteristics, yet are not bubbles according to our model. Finally, we present mathematical mechanisms for two phenomena that conform with our model, and show by computer simulation how they exhibit bubble behaviour.     

How to localize humanoids with a single camera?

In this paper, we propose a real-time vision-based localization approach for humanoid robots using a single camera as the only sensor. In order to obtain an accurate localization of the robot, we first build an accurate 3D map of the environment. In the map computation process, we use stereo visual SLAM techniques based on non-linear least squares optimization methods (bundle adjustment). Once we have computed a 3D reconstruction of the environment, which comprises of a set of camera poses (keyframes) and a list of 3D points, we learn the visibility of the 3D points by exploiting all the geometric relationships between the camera poses and 3D map points involved in the reconstruction. Finally, we use the prior 3D map and the learned visibility prediction for monocular vision-based localization. Our algorithm is very efficient, easy to implement and more robust and accurate than existing approaches. By means of visibility prediction we predict for a query pose only the highly visible 3D points, thus, speeding up tremendously the data association between 3D map points and perceived 2D features in the image. In this way, we can solve very efficiently the Perspective-n-Point (PnP) problem providing robust and fast vision-based localization. We demonstrate the robustness and accuracy of our approach by showing several vision-based localization experiments with the HRP-2 humanoid robot.     

How to shoot yourself right with a smartphone?

Virtual Reality - This article presents a new use case of using handheld augmented reality to set up a smartphone camera for taking a self-photograph needed for evaluating the user’s sports...     

What can a neuron learn with spike-timing-dependent plasticity?

Spiking neurons are very flexible computational modules, which can implement with different values of their adjustable synaptic parameters an enormous variety of different transformations F from input spike trains to output spike trains. We examine in this letter the question to what extent a spiking neuron with biologically realistic models for dynamic synapses can be taught via spike-timing-dependent plasticity (STDP) to implement a given transformation F. We consider a supervised learning paradigm where during training, the output of the neuron is clamped to the target signal (teacher forcing). The well-known perceptron convergence theorem asserts the convergence of a simple supervised learning algorithm for drastically simplified neuron models (McCulloch-Pitts neurons). We show that in contrast to the perceptron convergence theorem, no theoretical guarantee can be given for the convergence of STDP with teacher forcing that holds for arbitrary input spike patterns. On the other hand, we prove that average case versions of the perceptron convergence theorem hold for STDP in the case of uncorrelated and correlated Poisson input spike trains and simple models for spiking neurons. For a wide class of cross-correlation functions of the input spike trains, the resulting necessary and sufficient condition can be formulated in terms of linear separability, analogously as the well-known condition of learnability by perceptrons. However, the linear separability criterion has to be applied here to the columns of the correlation matrix of the Poisson input. We demonstrate through extensive computer simulations that the theoretically predicted convergence of STDP with teacher forcing also holds for more realistic models for neurons, dynamic synapses, and more general input distributions. In addition, we show through computer simulations that these positive learning results hold not only for the common interpretation of STDP, where STDP changes the weights of synapses, but also for a more realistic interpretation suggested by experimental data where STDP modulates the initial release probability of dynamic synapses.     

Controllers of a Given Radius of Stability Margin: Their Design by the H ∞-approach with Regard for External Disturbances

Output controllers for multivariate linear systems are designed such that they ensure, besides a given radius of stability margin for the physical input or output of the controlled object, a given radius of steady state characterized by the operation accuracy of a closed-loop system for adjusted variables. This design problem is reduced to a special H -optimization problem and the result is purely of sufficient type. It is solved numerically in the state space by the linear matrix inequalities method of MATLAB.     

Review article Synergy in remote sensing-what's in a pixel?

We address various questions that arise from the fact that a pixel or the related instantaneous field-of-view (IFOV) on the ground is often larger than we would like it to be.The problems arise as a penalty imposed by technology for the fact that a spacecraft gives an overview of a very large area. We study the question of why the pixel size is important when one studies satellite imagery and also some questions related to the factors that contribute to the recorded signal in a remotely-sensed data set. This includes a discussion of the instantaneous field-of-view, both from the simple geometrical point of view and from a more physical point of view. It also involves a study of the point spread function and some discussion of the problems associated with the determination of the point spread function of a given scanner. The questions of the calibration of the detectors in an instrument and of the intercalibration of nominally identical members of a series of instruments are also considered. The integration of remotely-sensed data into a GIS almost inevitably involves resampling and this leads to further complications in understanding the origin of the signal (digital number, DN) associated with a given pixel. The effects of different methods of interpolation are considered as well as the consequences of resampling in relation to the classification of an image. Several other topics are also considered and these include (a) the achievement of geometrical rectification with an error substantially smaller than (e.g., only 20 per cent of) the length of the edge of the instantaneous field-of-view, (b) data compression or upscaling, (c) mixed pixels, and (d) the study of sub-IFOV size objects. The general conclusion is that it is important to realise that what contributes to producing the digital number on a computer tape or in a disk file of an image is not a simple thing. There is no simple answer to the question 'what exactly gives rise to the signal detected and recorded in a pixel in a remotely-sensed image?' The main point to be made is to try to ensure that it is realised that there is a problem and to give some indication of the nature of that problem.     

Does cyberbullying overlap with school bullying when taking modality of involvement into account?

Education professionals and researchers are concerned by school bullying and cyberbullying because of its repercussions on students’ health and the school climate. However, only a few studies investigating the impact of school versus cyberbullying have systematically explored whether student victims and perpetrators are involved in school bullying only, cyberbullying only, or both. The aim of the present study was thus to examine the possible overlap, as well as the similarities and/or differences, between these two forms of bullying when taking modality of involvement into account. Individual interviews were conducted with 1422 junior high- and high-school students (girls = 43%, boys = 57%, mean age = 14.3 ± 2.7 years). Results showed that cyberbullying and school bullying overlapped very little. The majority of students involved in cyberbullying were not simultaneously involved in school bullying. Moreover, results indicated that psychosocial problems (psychological distress, social disintegration, general aggression) varied according to the form of bullying. Victims of school bullying had greater internalizing problems than cybervictims, while school bullies were more aggressive than cyberbullies. Given the sizable proportion of adolescents involved in bullying (school and cyber) and its significant relationship with mental health, the issue warrants serious attention from school and public health authorities.     

Do people with social anxiety feel anxious about interacting with a robot?

AI & SOCIETY - To investigate whether people with social anxiety have less actual and “anticipatory” anxiety when interacting with a robot compared to interacting with a person, we...