Physical force-sensitive touch responses in liquid crystal-gated-organic field-effect transistors with polymer dipole control layers

We report the sensing performances of liquid crystal-gated-organic field-effect transistors with a polymer dipole layer (DCL-LC-g-OFETs) upon physical touches. The DCL-LC-g-OFET devices, which were fabricated by employing 4-cyano-4’-pentylbiphenyl (5CB) as a sensing gate insulating layer, poly(methyl methacrylate) (PMMA) DCL, and 50 nm-thick poly(3-hexylthiophene) (P3HT) channel layer, which were optically semi-transparent and exhibited p-type transistor behavior. A pencil-like load (0.6 g–4.8 g) was introduced as a means for physical touch, while a human finger was used to examine the practical sensing capability of devices. Results showed that the drain current responded quickly upon physical touch and increased linearly with the strength of physical touch. The response time upon physical touch was slightly affected by the touch strength but was as fast as less than 1 s, while the drain current signals were quite reproducible and stable even after repeated physical touches. The present DCL-LC-g-OFET devices exhibited excellent sensing performances and reproducibility upon the human finger touch.     

Mining human mobility patterns from social geo-tagged data

Online social networks allow users to tag their posts with geographical coordinates collected through the GPS interface of smart phones. The time- and geo-coordinates associated with a sequence of posts/tweets manifest the spatial–temporal movements of people in real life. This paper aims to analyze such movements to discover people and community behavior. To this end, we defined and implemented a novel methodology to mine popular travel routes from geo-tagged posts. Our approach infers interesting locations and frequent travel sequences among these locations in a given geo-spatial region, as shown from the detailed analysis of the collected geo-tagged data.     

THE INFLUENCE OF A STABLE DIET AND REGULAR WORK ON BODY WEIGHT AND CAPACITY FOR EXERCISE IN AFRICAN MINE RECRUITS

In 20 African mine labourers there was a significant average gain in weight from 122 lb on recruitment to 128 lb after one month, as a, result of a stable diet and regular physical labour. The mean estimated maximum oxygen capacity rose significantly from 2·32 l to 2·79 l after one month, with a further slight rise to 2·83 l after four months. On each of the three occasions that these men were studied maximum oxygen capacity was highly correlated with gross body weight, the correlation coefficients rising from 0·59 to 0·70 after one month and to 0·83 after four months. Some exceptions to the general rule of ‘ the heavier the man the higher his oxygen capacity ’ are discussed. The ratio of oxygen intake to rate of work did not alter significantly, indicating that the subjects did not become more efficient in the unitization of oxygen. Subjects ventilated 30 per cent more air through their lungs in order to take in one litre of oxygen per min for work at 6,000 feat altitude than do men at sea level.     

Acute impairment of the sensitivity of skin mechanoreceptive units caused by vibration exposure of the hand

The thresholds of single mechanoreceptive afferent units, innervating the glabrous skin of the human hand to sinusoidal skin indentations at 2, 20 or 200 Hz were measured before and after 2 min powerful vibration exposures at the same frequencies. The corresponding psychophysical thresholds were measured in collateral experiments while still monitoring the unit responses. An acute but temporary rise in threshold occurred as a consequence of the vibration exposure in three different unit types (FA I, FA II and SA I). A close correlation was found between the neural and psychophysical thresholds with regard to the magnitudes of the shifts and the time courses of the recovery, provided that the thresholds were measured at the appropriate frequencies (i.e. at 200, 20 and 2 Hz while recording from FA II, FA I and SA I units, respectively). It was concluded that the acute impairment of tactile sensibility caused by vibration exposure, as earlier observed in psychophysical studies, most likely can be explained by a depression of the excitability of the mechanoreceptive afferent units.     

A weighted full-reference image quality assessment based on visual saliency

In full reference image quality assessment (IQA), the images without distortion are usually employed as reference, while the structures in both reference images and distorted images are ignored and all pixels are equally treated. In addition, the role of human visual system (HVS) is not taken account into subjective IQA metric. In this paper, a weighted full-reference image quality metric is proposed, where a weight imposed on each pixel indicates its importance in IQA. Furthermore, the weights can be estimated via visual saliency computation, which can approximate the subjective IQA via exploiting the HVS. In the experiments, the proposed metric is compared with several objective IQA metrics on LIVE release 2 and TID 2008 database. The results demonstrate that SROCC and PLCC of the proposed metric are 0.9647 and 0.9721, respectively,which are higher than other methods and it only takes 427.5 s, which is lower than that of most other methods.     

Classification of human motions

Stages in the development of the classification for human motions are reviewed from the 17th century up to the present day, with special emphasis on the discrete events approach to the classification of human motions as advocated by the Gilbreths. It is put forward that this approach is inappropriate both from the psychological and the physiological view point; while at the same time it is emphasized that, although the therblig approach contributed significantly to the understanding of human motions and skills, nevertheless it may be more harmful than beneficial in the long run. The additive properties of the discrete events approach to the analysis of human motions are considered. Results of the investigations reported here suggest that, in the performance of repetitive tasks of the nature described here, the therblig times of the task are independent units within a work cycle, when analysed by means of 100 cycles. Thus, the times are additive in the mathematical sense, but when the same task is repeated only once, or a very few times, and analysed by single cycles, the therblig times form an integrated part of the entire work cycle and, therefore, their times are not additive in the mathematical sense.     

Designing a personal informatics system for users without experience in self-tracking: a case study

Thanks to the advancements in ubiquitous and wearable technologies, Personal Informatics (PI) systems can now reach a larger audience of users. However, it is not still clear whether this kind of tool can fit the needs of their daily lives. Our research aims at identifying specific barriers that may prevent the widespread adoption of PI and finding solutions to overcome them. We requested users without competence in self-tracking to use different PI instruments during their daily practices, identifying five user requirements by which to design novel PI tools. On such requirements, we developed a new system that can stimulate the use of these technologies, by enhancing the perceived benefits of collecting personal data. Then, we explored how naïve and experienced users differently explore their personal data in our system through a user trial. Results showed that the system was successful at helping individuals manage and interpret their own data, validated the usefulness of the requirements found and inspired three further design opportunities that could orient the design of future PI systems.     

Need fulfillment and experiences on social media: A case on Facebook and WhatsApp

With an increasing inflow and outflow of users from social media, understanding the factors the drive their adoption becomes even more pressing. This paper reports on a study with 494 users of Facebook and WhatsApp. Different from traditional uses & gratifications studies that probe into typical uses of social media, we sampled users' single recent, outstanding (either satisfying or unsatisfying) experiences, based on a contemporary theoretical and methodological framework of 10 universal human needs. Using quantitative and qualitative analyses, we found WhatsApp to unlock new opportunities for intimate communications, Facebook to be characterized by primarily non-social uses, and both media to be powerful lifelogging tools. Unsatisfying experiences were primarily rooted in the tools' breach of offline social norms, as well in content fatigue and exposure to undesirable content in the case of Facebook. We discuss the implications of the findings for the design of social media.