Indoor localization using fine time measurement (FTM) round-trip time (RTT) with respect to cooperating Wi-Fi access points (APs) has been shown to work well and provide 1-2 m accuracy in both 2D and ...3D applications. This approach depends on APs implementing the IEEE 802.11-2016 (also known as IEEE 802.11mc) Wi-Fi standard ("two-sided" RTT). Unfortunately, the penetration of this Wi-Fi protocol has been slower than anticipated, perhaps because APs tend not to be upgraded as often as other kinds of electronics, in particular in large institutions-where they would be most useful. Recently, Google released Android 12, which also supports an alternative "one-sided" RTT method that will work with legacy APs as well. This method cannot subtract out the "turn-around" time of the signal, and so, produces distance estimates that have much larger offsets than those seen with two-sided RTT-and the results are somewhat less accurate. At the same time, this method makes possible distance measurements for many APs that previously could not be used. This increased accessibility can compensate for the decreased accuracy of individual measurements. We demonstrate here indoor localization using
RTT with respect to legacy APs that do not support IEEE 802.11-2016. The accuracy achieved is 3-4 m in cluttered environments with few line-of-sight readings (and using only 20 MHz bandwidths). This is not as good as for
RTT, where 1-2 m accuracy has been achieved (using 80 MHz bandwidths), but adequate for many applications A wider Wi-Fi channel bandwidth would increase the accuracy further. As before, Bayesian grid update is the preferred method for determining position and positional accuracy, but the observation model now is different from that for two-sided RTT. As with two-sided RTT, the probability of an RTT measurement below the true distance is very low, but, in the other direction, the range of measurements for a given distance can be much wider (up to well over twice the actual distance). We describe methods for formulating useful observation models. As with two-sided RTT, the offset or bias in distance measurements has to be subtracted from the reported measurements. One difference is that here, the offsets are large (typically in the 2400-2700 m range) because of the "turn-around time" of roughly 16 μs (i.e., about two orders of magnitude larger than the time of flight one is attempting to measure). We describe methods for estimating these offsets and for minimizing the effort required to do so when setting up an installation with many APs.
Summary
The aim of our study was to evaluate the performance of different durations of active pre‐operative skin‐surface warming (pre‐warming) to prevent peri‐operative hypothermia and postoperative ...shivering. We randomly assigned 200 patients, scheduled for surgery of 30–90 min under general anaesthesia, to receive passive insulation or forced‐air skin surface warming for 10, 20 or 30 min. Body temperature was measured at the tympanic membrane. Shivering was graded by visual inspection. There were significant differences in changes of core temperature between the non‐pre‐warmed group and all the pre‐warmed groups (p < 0.00001), but none between the three pre‐warmed groups (p = 0.54). Without pre‐warming, 38/55 (69%) patients became hypothermic (< 36 °C) at the end of anaesthesia, whereas only 7/52 (13%), 3/43 (7%) and 3/50 (6%) patients following 10, 20 or 30 min pre‐warming, respectively, became hypothermic (p < 0.001 vs no pre‐warming). Shivering was observed in 10 patients without, and in three, three and one patients with pre‐warming in the respective groups (p = 0.02). Pre‐warming of patients for only 10 or 20 min before general anaesthesia mostly prevents hypothermia and reduces shivering.
Spinal cord injuries often occur at the cervical level above the phrenic motor pools, which innervate the diaphragm. The effects of impaired breathing are a leading cause of death from spinal cord ...injuries, underscoring the importance of developing strategies to restore respiratory activity. Here we show that, after cervical spinal cord injury, the expression of chondroitin sulphate proteoglycans (CSPGs) associated with the perineuronal net (PNN) is upregulated around the phrenic motor neurons. Digestion of these potently inhibitory extracellular matrix molecules with chondroitinase ABC (denoted ChABC) could, by itself, promote the plasticity of tracts that were spared and restore limited activity to the paralysed diaphragm. However, when combined with a peripheral nerve autograft, ChABC treatment resulted in lengthy regeneration of serotonin-containing axons and other bulbospinal fibres and remarkable recovery of diaphragmatic function. After recovery and initial transection of the graft bridge, there was an unusual, overall increase in tonic electromyographic activity of the diaphragm, suggesting that considerable remodelling of the spinal cord circuitry occurs after regeneration. This increase was followed by complete elimination of the restored activity, proving that regeneration is crucial for the return of function. Overall, these experiments present a way to markedly restore the function of a single muscle after debilitating trauma to the central nervous system, through both promoting the plasticity of spared tracts and regenerating essential pathways.
•The problem of synchronous scheduling for both logistics services and processing services in cloud manufacturing is studied based on its mathematical description.•A collaborative optimization ...algorithm which we call COOPS is proposed for logistics and processing services to generate scheduling solutions for both processing tasks and logistics tasks at the same time.•Experimental results show that the proposed method obtains a shorter average completion time for all tasks in different scenarios than typical optimization algorithms such as pattern search, particle swarm optimization and simulated annealing.
Efficient service scheduling is an important technique to support collaborative manufacturing platforms such as IoT-enable manufacturing systems and cloud manufacturing. In the past few years, optimization problems for processing services have attracted the most attention of researchers and practitioners in terms of task matching, service selection, and scheduling. Logistics services, as another important kind of services in the cloud manufacturing environment, need to be explored further, beyond parameters of costs and time, in order to obtain more efficient task execution and more timely product delivery. In this paper, we consider the problem of synchronous scheduling of logistics services and processing services in cloud manufacturing. Based on the mathematical description, we present a collaborative optimization algorithm for logistics and processing services which we call COOPS to generate scheduling solutions for both processing tasks and logistics tasks at the same time. Typical optimization algorithms such as pattern search, particle swarm optimization and simulated annealing are compared with the proposed algorithm to show their performance on the average completion time of all manufacturing tasks. Results show that the proposed method obtains a shorter average completion time for all tasks in different scenarios.
The IEEE 802.11mc WiFi standard provides a protocol for a cellphone to measure its distance from WiFi access points (APs). The position of the cellphone can then be estimated from the reported ...distances using known positions of the APs. There are several “multilateration” methods that work in relatively open environments. The problem is harder in a typical residence where signals pass through walls and floors. There, Bayesian cell update has shown particular promise. The Bayesian grid update method requires an “observation model” which gives the conditional probability of observing a reported distance given a known actual distance. The parameters of an observation model may be fitted using scattergrams of reported distances versus actual distance. We show here that the problem of fitting an observation model can be reduced from two dimensions to one. We further show that, perhaps surprisingly, a “double exponential” observation model fits real data well. Generating the test data involves knowing not only the positions of the APs but also that of the cellphone. Manual determination of positions can limit the scale of test data collection. We show here that “boot strapping,” using results of a Bayesian grid update method as a proxy for the actual position, can provide an accurate observation model, and a good observation model can nearly double the accuracy of indoor positioning. Finally, indoors, reported distance measurements are biased to be mostly longer than the actual distances. An attempt is made here to detect this bias and compensate for it.
Accurate air temperature observations in urban areas are important for meteorology and energy demand planning. They are indispensable to study the urban heat island effect and the adverse effects of ...high temperatures on human health. However, the availability of temperature observations in cities is often limited. Here we show that relatively accurate air temperature information for the urban canopy layer can be obtained from an alternative, nowadays omnipresent source: smartphones. In this study, battery temperatures were collected by an Android application for smartphones. A straightforward heat transfer model is employed to estimate daily mean air temperatures from smartphone battery temperatures for eight major cities around the world. The results demonstrate the enormous potential of this crowdsourcing application for real‐time temperature monitoring in densely populated areas.
Key Points
Daily mean air temperatures can be estimated from smartphones for eight cities
Smartphones hold a promise for monitoring environmental variables
Entanglement generation can be robust against certain types of noise in approaches that deliberately incorporate dissipation into the system dynamics. The presence of additional dissipation channels ...may, however, limit fidelity and speed of the process. Here we show how quantum optimal control techniques can be used to both speed up the entanglement generation and increase the fidelity in a realistic setup, whilst respecting typical experimental limitations. For the example of entangling two trapped ion qubits (Lin et al 2013 Nature 504 415), we find an improved fidelity by simply optimizing the polarization of the laser beams utilized in the experiment. More significantly, an alternate combination of transitions between internal states of the ions, when combined with optimized polarization, enables faster entanglement and decreases the error by an order of magnitude.
ABSTRACT
In this case report, we highlight minocycline-induced scleral hyperpigmentation, combined with ear and fingernail discoloration that developed after over 15 years of use for rosacea in a ...78-year-old male with multiple medical comorbidities. Minocycline, a tetracycline antibiotic, is used to treat rosacea and acne as well as some orthopedic infections. It is typically used for extended periods of time; long-term use of minocycline is associated with hyperpigmentation of the sclera, conjunctiva, retina, teeth, skin, subcutaneous fat, oral mucosa, tympanic membrane, and gingiva. This case highlights that hyperpigmentation is more likely to occur in older patients than in younger patients. Scleral hyperpigmentation is not associated with vision loss; however, cosmetic concerns can prompt discontinuation of minocycline. Nonetheless, after cessation, the lesions persist in some patients. Monitoring for hyperpigmentation in patients using minocycline is important, as the hyperpigmentation is more likely to be permanent with long-term use.
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