In this paper we address the problem of autonomously localizing multiple gas/odor sources in an indoor environment without a strong airflow. To do this, a robot iteratively creates an occupancy grid map. The produced map shows the probability each discrete cell contains a source. Our approach is based on a recent adaptation (Jakuba, 2007) [16] to traditional Bayesian occupancy grid mapping for chemical source localization problems. The approach is less sensitive, in the considered scenario, to the choice of the algorithm parameters. We present experimental results with a robot in an indoor uncontrolled corridor in the presence of different ejecting sources proving the method is able to build reliable maps quickly (5.5 minutes in a 6 m×2.1 m area) and in real time. 相似文献
The tensor rankA of the linear spaceA generated by the set of linearly independent matricesA1, A2, …, Ap, is the least integert for wich there existt diadsu(r)v(r)τ, τ=1,2,...,t, such that
. IfA=n+k,k≪n then some computational problems concerning matricesA∈A can be solyed fast. For example the parallel inversion of almost any nonsingular matrixA∈A costs 3 logn+0(log2k) steps with max(n2+p (n+k), k2n+nk) processors, the evaluation of the determinant ofA can be performed by a parallel algorithm in logp+logn+0 (log2k) parallel steps and by a sequential algorithm inn(1+k2)+p (n+k)+0 (k3) multiplications. Analogous results hold to accomplish one step of bisection method, Newton's iterations method and shifted
inverse power method applied toA−λB in order to compute the (generalized) eigenvalues provided thatA, B∈A. The same results hold if tensor rank is replaced by border rank. Applications to the case of banded Toeplitz matrices are
shown.
Dedicated to Professor S. Faedo on his 70th birthday
Part of the results of this paper has been presented at the Oberwolfach Conference on Komplexitatstheorie, November 1983 相似文献
We present an ultrafast transient absorption spectroscopy system in the visible combining high-sensitivity broadband detection with extreme temporal resolution. The instrument is based on an ultrabroadband sub-10 fs optical parametric amplifier coupled to an optical multichannel analyzer with fast electronics, enabling single-shot detection at 1 kHz repetition rate. For a given pump-probe delay tau, we achieve a differential transmission (DeltaTT) sensitivity of the order of 10(-4) over the lambda(pr)=490-720 nm probe wavelength range by averaging over 1000 shots, allowing the acquisition of complete two-dimensional DeltaTT (lambda(pr),Tau) maps within a few minute measurement time. We present application examples highlighting the capability of this instrument to observe ultrafast dynamical processes, follow impulsively excited vibrational motions with frequency as high as 3000 cm(-1) (11 fs period), and determine the probe wavelength dependence of amplitude and phase of the oscillations. 相似文献
The Fitts’ law describes a correlation between the time needed to complete basic tasks such as pointing movements and the
level of knowledge of the specific target to be reached. While it has been largely proved in normal gravity, very few experiments
have been carried out in altered gravitational conditions. In our experiment, four subjects were positioned in front of a
panel where round targets were placed along a circumference. They carried out pointing movements towards the targets when
these were switched on. The task time was acquired and processed off-line. In all the cases, the performance of each subject
have been significantly modified in the altered gravitational environment and, in particular, hypergravity seems to affect
motor performance more considerably than microgravity. Even if experiments involving several subjects and more complex tasks
have to be carried out in order to confirm our findings, these results show that ergonomics could be strongly affected by
the modification of gravity, especially during the first phase of exposure to gravity alteration. 相似文献
We previously reported that c-KIT+ human amniotic-fluid derived stem cells obtained from leftover samples of routine II trimester prenatal diagnosis (fetal hAFS) are endowed with regenerative paracrine potential driving pro-survival, anti-fibrotic and proliferative effects. hAFS may also be isolated from III trimester clinical waste samples during scheduled C-sections (perinatal hAFS), thus offering a more easily accessible alternative when compared to fetal hAFS. Nonetheless, little is known about the paracrine profile of perinatal hAFS. Here we provide a detailed characterization of the hAFS total secretome (i.e., the entirety of soluble paracrine factors released by cells in the conditioned medium, hAFS-CM) and the extracellular vesicles (hAFS-EVs) within it, from II trimester fetal- versus III trimester perinatal cells. Fetal- and perinatal hAFS were characterized and subject to hypoxic preconditioning to enhance their paracrine potential. hAFS-CM and hAFS-EV formulations were analyzed for protein and chemokine/cytokine content, and the EV cargo was further investigated by RNA sequencing. The phenotype of fetal- and perinatal hAFS, along with their corresponding secretome formulations, overlapped; yet, fetal hAFS showed immature oxidative phosphorylation activity when compared to perinatal ones. The profiling of their paracrine cargo revealed some differences according to gestational stage and hypoxic preconditioning. Both cell sources provided formulations enriched with neurotrophic, immunomodulatory, anti-fibrotic and endothelial stimulating factors, and the immature fetal hAFS secretome was defined by a more pronounced pro-vasculogenic, regenerative, pro-resolving and anti-aging profile. Small RNA profiling showed microRNA enrichment in both fetal- and perinatal hAFS-EV cargo, with a stably- expressed pro-resolving core as a reference molecular signature. Here we confirm that hAFS represents an appealing source of regenerative paracrine factors; the selection of either fetal or perinatal hAFS secretome formulations for future paracrine therapy should be evaluated considering the specific clinical scenario. 相似文献
The cover image is based on the Research Article Differential scanning calorimetry study of cross‐nucleation between polymorphs in isotactic poly(1‐butene) by Bao Wang et al. DOI: 10.1002/pi.5595 .
Evolutionary Robotics is a powerful method to generate efficient controllers with minimal human intervention, but its applicability to real-world problems remains a challenge because the method takes long time and it requires software simulations that do not necessarily transfer smoothly to physical robots. In this paper we describe a method that overcomes these limitations by evolving robots for the ability to adapt on-line in few seconds. Experiments show that this method require less generations and smaller populations to evolve, that evolved robots adapt in a few seconds to unpredictable change-including transfers from simulations to physical robots- and display non-trivial behaviors. Robots evolved with this method can be dispatched to other planets and to our homes where they will autonomously and quickly adapt to the specific properties of their environments if and when necessary. 相似文献