Gyroscopic stabilisers for powered two-wheeled vehicles

© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. This paper illustrates the potential of a gyroscopic stabiliser for the stabilisation of single-track vehicles, at low and high speed as well as during braking. Alternative systems are considered, including single and twin counter-rotating gyroscopes, spinning and precessing with respect to different axes, either freely (passive stabilisers) or in a controlled way (active stabilisers). A suitable mathematical model has been developed and stability has been investigated both by eigenvalue calculation and time domain simulations. It has been found that the most effective configuration is one where the gyroscope(s) spin with respect to an axis parallel to the wheels' spin axis and swing with respect to the vehicle yaw axis. Passive systems may effectively stabilise both weave and wobble at medium and high speed, but cannot stabilise the vehicle at low and zero speed. On the contrary, actively controlled gyroscopes are capable of stabilising the vehicle in its whole range of operating speed, as well as during braking. The alteration of the original vehicle handling characteristics is negligible when active counter-rotating gyroscopes are used, and still acceptable if a single gyroscope is adopted instead

Series Hybrid Electric Vehicle Simultaneous Energy Management and Driving Speed Optimization

The energy management (EM) and driving speed co-optimization of a series hybrid electric vehicle (S-HEV) for minimizing fuel consumption is addressed in this article on the basis of a suitably modeled series powertrain architecture. The paper proposes a novel strategy that finds the optimal driving speed simultaneously with the energy source power split for the drive mission specified in terms of the road geometry and travel time. Such a combined optimization task is formulated as an optimal control problem that is solved by an indirect optimal control method, based on Pontryagin’s minimum principle. The optimization scheme is tested under a rural drive mission by extensive comparisons with conventional methods that deal with either speed optimization only or EM strategies with given driving cycles. The comparative results show the superior performance of the proposed method and provide further insight into efficient driving

Motivation of health surveillance assistants in Malawi: A qualitative study

Background: Motivation of health workers is a critical component of performance and is shaped by multiple factors. This study explored factors that influence motivation of health surveillance assistants (HSAs) in Malawi, with the aim of identifying interventions that can be applied to enhance motivation and performance of HSAs.Methods: A qualitative study capturing the perspectives of purposively selected participants was conducted in two districts: Salima and Mchinji. Participants included HSAs, health managers, and various community members. Data were collected through focus group discussions (n = 16) and in-depth interviews (n = 44). The study sample was comprised of 112 women and 65 men. Qualitative data analysis was informed by existing frameworks on factors influencing health worker motivation.Results: Our analysis identified five key themes shaping HSA motivation: salary, accommodation, human resource management, supplies and logistics, and community links. Each of these played out at different levels—individual, family, community, and organisational—with either positive or negative effects. Demotivating factors related primarily to the organisational level, while motivating factors were more often related to individual, family, and community levels. A lack of financial incentives and shortages of basic supplies and materials were key factors demotivating HSAs. Supervision was generally perceived as unsupportive, uncoordinated, and top-down. Most HSAs complained of heavy workload. Many HSAs felt further recognition and support from the Ministry of Health, and the development of a clear career pathway would improve their motivation.Conclusions: Factors shaping motivation of HSAs are complex and multilayered; experiences at one level will impact other levels. Interventions are required to enhance HSA motivation, including strengthening the supervision system, developing career progression pathways, and ensuring clear and transparent incentives. HSAs have unique experiences, and there is need to hear and address these to better enable HSAs to cope with the challenging conditions they work in

A systematic approach to generating accurate neural network potentials: the case of carbon

Availability of affordable and widely applicable interatomic potentials is the key needed to unlock the riches of modern materials modeling. Artificial neural network-based approaches for generating potentials are promising; however, neural network training requires large amounts of data, sampled adequately from an often unknown potential energy surface. Here we propose a self-consistent approach that is based on crystal structure prediction formalism and is guided by unsupervised data analysis, to construct an accurate, inexpensive, and transferable artificial neural network potential. Using this approach, we construct an interatomic potential for carbon and demonstrate its ability to reproduce first principles results on elastic and vibrational properties for diamond, graphite, and graphene, as well as energy ordering and structural properties of a wide range of crystalline and amorphous phases

Spectroscopic distances of 28 nearby star candidates

28 hitherto neglected candidates for the Catalogue of Nearby Stars (CNS) were investigated to verify their classification and to improve their distance estimates. All targets had at least a preliminary status of being nearby dwarf stars based on their large proper motions and relatively faint magnitudes. Better photometric and/or spectroscopic distances were required for selecting stars which are worth the effort of trigonometric parallax measurements. Low-resolution spectra were obtained with NASPEC at the Tautenburg 2m telescope and with CAFOS at the Calar Alto 2.2m telescope. The spectral types of M-type stars were determined by direct comparison of the target's spectra with those of comparison stars of known spectral types observed with the same instrument. The classification of earlier types was done based on comparison with published spectral libraries. The majority were classified as M dwarfs including 11 stars within 25 pc. The fainter component of LDS 1365, previously thought to form a nearby common proper motion pair, is according to our results an unrelated high-velocity background star. For several other nearby common proper motion pairs our distance estimates of the fainter components are in good agreement with Hipparcos distances of the brighter components. (abridged)Comment: 5 pages, 4 figures, accepted by Astron. Astrophy

Effectiveness of different modalities of psychotherapeutic treatment for patients with cluster C personality disorders: results of a large prospective multicentre study.

Abstract BACKGROUND: No previous studies have compared the effectiveness of different modalities of psychotherapeutic treatment, as defined by different settings and durations, for patients with cluster C personality disorders. The aim of this multicentre study wa

A characterization of the molecular phenotype and inflammatory response of schizophrenia patient-derived microglia-like cells

Different lines of evidence support a causal role for microglia in the pathogenesis of schizophrenia. However, how schizophrenia patient-derived microglia are affected at the phenotypic and functional level is still largely unknown. We used a recently described model to induce patient-derived microglia-like cells and used this to analyze changes in the molecular phenotype and function of myeloid cells in schizophrenia. We isolated monocytes from twenty recent-onset schizophrenia patients and twenty non-psychiatric controls. We cultured the cells towards an induced microglia-like phenotype (iMG), analyzed the phenotype of the cells by RNA sequencing and mass cytometry, and their response to LPS. Mass cytometry showed a high heterogeneity of iMG in cells derived from patients as well as controls. The prevalence of two iMG clusters was significantly higher in schizophrenia patients (adjusted p-value <0.001). These subsets are characterized by expression of ApoE, Ccr2, CD18, CD44, and CD95, as well as IRF8, P2Y(12), Cx3cr1 and HLA-DR. In addition, we found that patient derived iMG show an enhanced response to LPS, with increased secretion of TNF-alpha. Further studies are needed to replicate these findings, to determine whether similar subclusters are present in schizophrenia patients in vivo, and to address how these subclusters are related to the increased response to LPS, as well as other microglial functions

Validation of Case-Finding Algorithms Derived from Administrative Data for Identifying Adults Living with Human Immunodeficiency Virus Infection

OBJECTIVE: We sought to validate a case-finding algorithm for human immunodeficiency virus (HIV) infection using administrative health databases in Ontario, Canada. METHODS: We constructed 48 case-finding algorithms using combinations of physician billing claims, hospital and emergency room separations and prescription drug claims. We determined the test characteristics of each algorithm over various time frames for identifying HIV infection, using data abstracted from the charts of 2,040 randomly selected patients receiving care at two medical practices in Toronto, Ontario as the reference standard. RESULTS: With the exception of algorithms using only a single physician claim, the specificity of all algorithms exceeded 99%. An algorithm consisting of three physician claims over a three year period had a sensitivity and specificity of 96.2% (95% CI 95.2%-97.9%) and 99.6% (95% CI 99.1%-99.8%), respectively. Application of the algorithm to the province of Ontario identified 12,179 HIV-infected patients in care for the period spanning April 1, 2007 to March 31, 2009. CONCLUSIONS: Case-finding algorithms generated from administrative data can accurately identify adults living with HIV. A relatively simple "3 claims in 3 years" definition can be used for assembling a population-based cohort and facilitating future research examining trends in health service use and outcomes among HIV-infected adults in Ontario