Probabilistic multiple pedestrian walking force model including pedestrian inter- and intra-subject variabilities

This is the final version. Available on open access from Hindawi via the DOI in this recordA probabilistic walking load model that accounts for inter- and intra-subject variabilities has been developed to generate synthetic vertical load waveforms induced by pedestrians. The mathematical model is based on a comprehensive database of continuously recorded pedestrian walking forces on an instrumented treadmill, having a wide range of walking frequencies. The proposed model is able to replicate temporal and spectral features of real walking forces, which is a significant advantage over conventional Fourier series models. The load model results in more realistic force time histories than previous models, since it incorporates significant components of the spectra that are omitted in Fourier series approaches. The proposed mathematical model can be implemented in vibration serviceability assessment of civil engineering structures, such as building floors and footbridges, to estimate more realistically dynamic structural responses due to people walkingQatar National Research Foundatio

Predictive protocol of flocks with small-world connection pattern

By introducing a predictive mechanism with small-world connections, we propose a new motion protocol for self-driven flocks. The small-world connections are implemented by randomly adding long-range interactions from the leader to a few distant agents, namely pseudo-leaders. The leader can directly affect the pseudo-leaders, thereby influencing all the other agents through them efficiently. Moreover, these pseudo-leaders are able to predict the leader's motion several steps ahead and use this information in decision making towards coherent flocking with more stable formation. It is shown that drastic improvement can be achieved in terms of both the consensus performance and the communication cost. From the industrial engineering point of view, the current protocol allows for a significant improvement in the cohesion and rigidity of the formation at a fairly low cost of adding a few long-range links embedded with predictive capabilities. Significantly, this work uncovers an important feature of flocks that predictive capability and long-range links can compensate for the insufficiency of each other. These conclusions are valid for both the attractive/repulsive swarm model and the Vicsek model.Comment: 10 pages, 12 figure

Evaluation of contemporary guidelines for floor vibration serviceability assessment

This is the author accepted manuscript. The final version is available from the publisher, Society for Experimental Mechanics.IMAC-XXXV,: 35th International Modal Analysis Conference, 30 January - 2 February 2017, Garden Grove, California, USATechnological advances in the construction sector and innovative lightweight and large span structural layouts in modern building floors increasingly mean that vibration serviceability is the governing design criterion. As this trend continues, excessive vibrations induced by human activities are becoming a significant concern. Prediction of floor vibrations at the design stage is often done using currently available design guidelines, such as AISC Design Guide 11, Concrete Society Technical Report 43 Appendix G, SCI P354, Concrete Centre CCIP-016 and HiVoSS. In this paper, the aforementioned design guidelines are used to predict the vibration responses of a typical office floor, which are then compared with the actual measured responses. It is clear that different guidelines provide different tolerance limits which make the satisfactory/unsatisfactory decision imprecise. The results show that the case-study floor is unsatisfactory according to CSTR43 App G and CCIP-016, whereas it satisfies the requirements of AISC-DG11, SCI P354 and HiVoSS. Nevertheless, the experimental vibration response indicates that there is a perceptible level of vibrations but with no adverse comments. These discrepancies highlight the need for a better prediction techniques and more reliable assessment criteria.The authors gratefully acknowledge the financial support of the Qatar National Research Fund (QNRF) through grant NPRP8- 836-2-353 entitled “A Unified Approach to Vibration Serviceability Assessment of Floors

Neuromyelitis optica spectrum disorder in three generations of a Chinese family

© 2019 Neuromyelitis optica spectrum disorder is an inflammatory demyelinating disease that is largely sporadic. Familial disease has been reported in one or two generations, although its basis remains unknown. We report here three subjects meeting diagnostic criteria for NMOSD in one family: a father and son, and the maternal aunt of the father. Anticipation, of 27 years, was apparent in transmission from father to son. Aquaporin-4 antibodies were observed in the aunt but not the father and son, nor in other family members. A putative pathogenic mutation in the NECL2 gene was not found in this pedigree. This first report of NMOSD in three generations of one family underlines the heterogeneity of familial NMOSD

Review of Pedestrian Load Models for Vibration Serviceability Assessment of Floor Structures

This is the final version. Available on open access from MDPI via the DOI in this recordInnovative design and technological advancements in the construction industry have resulted in an increased use of large, slender and lightweight floors in contemporary office buildings. Compounded by an ever-increasing use of open-plan layouts with few internal partitions and thus lower damping, floor vibration is becoming a governing limit state in the modern structural design originating from dynamic footfall excitations. This could cause annoyance and discomfort to building occupants as well as knock-on management and financial consequences for facility owners. This article presents a comprehensive review pertinent to walking-induced dynamic loading of low-frequency floor structures. It is intended to introduce and explain key walking parameters in the field as well as summarise the development of previous walking models and methods for vibration serviceability assessment. Although a number of walking models and design procedures have been proposed, the literature survey highlights that further work is required in the following areas; (1) the development of a probabilistic multi-person loading model which accounts for inter- and intra-subject variabilities, (2) the identification of walking paths (routes accounting for the effect of occupancy patterns on office floors) coupled with spatial distribution of pedestrians and (3) the production of a statistical spatial response approach for vibration serviceability assessment. A stochastic approach, capable of taking into account uncertainties in loading model and vibration responses, appears to be a more reliable way forward compared to the deterministic approaches of the past and there is a clear need for further research in this areaEngineering and Physical Sciences Research Council (EPSRC)Qatar National Research Foundatio

Orientation cues for high-flying nocturnal insect migrants: do turbulence-induced temperature and velocity fluctuations indicate the mean wind flow?

Migratory insects flying at high altitude at night often show a degree of common alignment, sometimes with quite small angular dispersions around the mean. The observed orientation directions are often close to the downwind direction and this would seemingly be adaptive in that large insects could add their self-propelled speed to the wind speed, thus maximising their displacement in a given time. There are increasing indications that high-altitude orientation may be maintained by some intrinsic property of the wind rather than by visual perception of relative ground movement. Therefore, we first examined whether migrating insects could deduce the mean wind direction from the turbulent fluctuations in temperature. Within the atmospheric boundary-layer, temperature records show characteristic ramp-cliff structures, and insects flying downwind would move through these ramps whilst those flying crosswind would not. However, analysis of vertical-looking radar data on the common orientations of nocturnally migrating insects in the UK produced no evidence that the migrants actually use temperature ramps as orientation cues. This suggests that insects rely on turbulent velocity and acceleration cues, and refocuses attention on how these can be detected, especially as small-scale turbulence is usually held to be directionally invariant (isotropic). In the second part of the paper we present a theoretical analysis and simulations showing that velocity fluctuations and accelerations felt by an insect are predicted to be anisotropic even when the small-scale turbulence (measured at a fixed point or along the trajectory of a fluid-particle) is isotropic. Our results thus provide further evidence that insects do indeed use turbulent velocity and acceleration cues as indicators of the mean wind direction

Health professionals' perceptions of cultural influences on stroke experiences and rehabilitation in Kuwait

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2012 Informa UK Ltd.Purpose: The aim of this study was to investigate the perceptions of health professionals who treat stroke patients in Kuwait regarding cultural influences on the experience of stroke and rehabilitation in Kuwait. Health professionals interviewed were from a variety of cultural backgrounds thus providing an opportunity to investigate how they perceived the influence of culture on stroke recovery and rehabilitation in Kuwait. Method: Semi-structured interviews were carried out with 12 health professionals with current/recent stroke rehabilitation experience in Kuwait, followed by thematic analysis of the verbatim transcripts. Results: The health professionals identified several features of the Kuwaiti culture that they believed affected the experiences of stroke patients. These were religious beliefs, family involvement, limited education and public information about stroke, prevailing negative attitudes toward stroke, access to finances for private treatment, social stigma and the public invisibility of disabled people, difficulties identifying meaningful goals for rehabilitation, and an acceptance of dependency linked with the widespread presence of maids and other paid assistants in most Kuwaiti homes. Conclusion: To offer culturally sensitive care, these issues should be taken into account during the rehabilitation of Kuwaiti stroke patients in their home country and elsewhere