Multi-user indoor optical wireless communication system channel control using a genetic algorithm

A genetic algorithm controlled multispot transmitter is demonstrated that is capable of optimising the received power distribution for randomly aligned single element receivers in multiple fully diffuse optical wireless communications systems with multiple mobile users. Using a genetic algorithm to control the intensity of individual diffusion spots, system deployment environment changes, user movement and user alignment can be compensating for, with negligible impact on the bandwidth and root mean square delay spread. It is shown that the dynamic range, referenced against the peak received power, can be reduced up to 27% for empty environments and up to 26% when the users are moving. Furthermore, the effect of user movement, that can perturb the channel up to 8%, can be reduced to within 5% of the optimised case. Compared to alternative bespoke designs that are capable of mitigating optical wireless channel drawbacks, this method provides the possibility of cost-effectiveness for mass-produced receivers in applications where end-user friendliness and mobility are paramount

Optical wireless for intravehicle communications : incorporating passenger presence scenarios

Through the implementation of a simple linearly scalable 1-W infrared (IR) transmitter, which is centrally located on the ceiling of a sports utility vehicle (SUV), and for 15 passenger configurations, an analysis into the received power, power deviation, minimum bandwidth, and maximum root-mean-square (RMS) delay spread is provided for the regions of the vehicle most likely to benefit from the deployment of intravehicle optical wireless (OW) communication systems. Several specific regions, including the areas around a passenger's legs, arms, necks, and shoulders, are shown to have beneficial channel characteristics for the use of personal electronics equipment such as laptops, tablet PCs, or wireless headphones. Similarly, a region around the headrest of the front seat is shown to have potential for the deployment of in-car entertainment solutions independent of the passenger configuration. This analysis, which is the first to introduce the concept of channel variation from multiple passenger configurations, aims to show that OW is a potential candidate for future intravehicular communication systems

Effect of Stocking Rate on Growing Juvenile Sunshine Bass, Morone chrysops × M. saxatilis, in an Outdoor Biofloc Production System

The biofloc technology production system is a production intensifying management strategy used primarily for culturing tilapia and penaeid shrimp, both of which can consume the biofloc. Other fish can be grown in biofloc systems because the biofloc serves to maintain water quality, metabolizing the ammonia excreted by intensively fed fish. A dose-response study was conducted in an outdoor biofloc system to begin quantifying the stocking rate-production function for sunshine bass, Morone chrysops x M. saxatilis, advanced fingerlings. Sunshine bass (2.9 ± 0.2 g/fish) were stocked into tanks at 50 to 250 fish/m2 in 50 fish/m2 increments. After 94 days, gross yields ranged from 1.4 to 3.1 kg/m3 and were independent of stocking rate. Harvested fish were separated into two size groups: smaller than 115 mm total length (target fish) and larger than 115 mm TL (jumper fish). Target fish increased linearly from 62% to 93% and jumpers decreased linearly from 38% to 7% of the population, respectively, as stocking rate increased. The outdoor biofloc system offers potential for intensifying the production of advanced sunshine bass fingerlings, but feed consumption appeared to be impeded by high total suspended solids concentrations. Further research is needed to optimize stocking rates and solids management

Co-designing interventions within quality improvement initiatives : notes from the field

Increasingly, quality improvement programmes are developed with an explicit mandate to involve patients, carers, and members of the public. A quality improvement and research programme in Northwest London has nearly a decade of experience in this field. This article provides an overview of how improvement initiatives supported by the programme have involved patients in the co-design of interventions within various clinical settings. Reflections on some of the challenges and facilitators are offered. Extending roles for patients beyond co- designing interventions to involving them in implementation offers new levels of engagement and transparenc

Free space optical in vehicular networks using rectangular guiding models

This letter introduces Free-Space Optical (FSO) Communication links in vehicular applications using potential guiding structures around a vehicle. An optical wireless communication system simulation is described which delivers received power, bandwidth, root mean square delay spread channel impulse response for purely diffuse and diffuse-specular materials with omnidirectional and directed transmitters. In the former case, a bandwidth of 225 MHz with a power deviation of 25% results at the exit. For the latter, a 75GHz bandwidth is available at best but with a power deviation of over 99% making receiver positioning critical. The impulse response is calculated using a Modified Monte Carlo algorithm taking into account up to 15 reflections. The effect of the pipe bend angle on the path loss is also presented and the simulation is supported with experimental work

A survey study of index food‐related allergic reactions and anaphylaxis management

Background:  Initial food‐allergic reactions are often poorly recognized and under‐treated. Methods:  Parents of food‐allergic children were invited to complete an online questionnaire, designed with Kids with Food Allergies Foundation , about their children’s first food‐allergic reactions resulting in urgent medical evaluation. Results:  Among 1361 reactions, 76% (95% CI 74–79%) were highly likely to represent anaphylaxis based on NIAID/FAAN criteria. Only 34% (95% CI 31–37%) of these were administered epinephrine. In 56% of these, epinephrine was administered by emergency departments; 20% by parents; 9% by paramedics; 8% by primary care physicians; and 6% by urgent care centers. In 26% of these, epinephrine was given within 15 min of the onset of symptoms; 54% within 30 min; 82% within 1 h; and 93% within 2 h. Factors associated with a decreased likelihood of receiving epinephrine for anaphylaxis included age <12 months, milk and egg triggers, and symptoms of abdominal pain and/or diarrhea. Epinephrine was more likely to be given to asthmatic children and children with peanut or tree nut ingestion prior to event. Post‐treatment, 42% of reactions likely to represent anaphylaxis were referred to allergists, 34% prescribed and/or given epinephrine auto‐injectors, 17% trained to use epinephrine auto‐injectors, and 19% given emergency action plans. Of patients treated with epinephrine, only half (47%) were prescribed epinephrine auto‐injectors. Conclusions:  Only one‐third of initial food‐allergic reactions with symptoms of anaphylaxis were recognized and treated with epinephrine. Fewer than half of patients were referred to allergists. There is still a need to increase education and awareness about food‐induced anaphylaxis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93515/1/pai1315.pd

On the cyclically fully commutative elements of Coxeter groups

Let W be an arbitrary Coxeter group. If two elements have expressions that are cyclic shifts of each other (as words), then they are conjugate (as group elements) in W. We say that w is cyclically fully commutative (CFC) if every cyclic shift of any reduced expression for w is fully commutative (i.e., avoids long braid relations). These generalize Coxeter elements in that their reduced expressions can be described combinatorially by acyclic directed graphs, and cyclically shifting corresponds to source-to-sink conversions. In this paper, we explore the combinatorics of the CFC elements and enumerate them in all Coxeter groups. Additionally, we characterize precisely which CFC elements have the property that powers of them remain fully commutative, via the presence of a simple combinatorial feature called a band. This allows us to give necessary and sufficient conditions for a CFC element w to be logarithmic, that is, ℓ(wk)=k⋅ℓ(w) for all k≥1, for a large class of Coxeter groups that includes all affine Weyl groups and simply laced Coxeter groups. Finally, we give a simple non-CFC element that fails to be logarithmic under these conditions