Estimated path information gain-based robot exploration under perceptual uncertainty

At present, the frontier-based exploration has been one of the mainstream methods in autonomous robot exploration. Among the frontier-based algorithms, the method of searching frontiers based on rapidly exploring random trees consumes less computing resources with higher efficiency and performs well in full-perceptual scenarios. However, in the partially perceptual cases, namely when the environmental structure is beyond the perception range of robot sensors, the robot often lingers in a restricted area, and the exploration efficiency is reduced. In this article, we propose a decision-making method for robot exploration by integrating the estimated path information gain and the frontier information. The proposed method includes the topological structure information of the environment on the path to the candidate frontier in the frontier selection process, guiding the robot to select a frontier with rich environmental information to reduce perceptual uncertainty. Experiments are carried out in different environments with the state-of-the-art RRT-exploration method as a reference. Experimental results show that with the proposed strategy, the efficiency of robot exploration has been improved obviously.

Description of a new minute frog of the genus Pristimantis (Anura: Strabomantidae) from Cordillera del Condor, Ecuador

We describe a new species of Pristimantis from southern Ecuador, province of Zamora Chinchipe. The new species is closely related to an undescribed species of Pristimantis from Reserva Tapichalaca, Ecuador and with species of a clade historically assigned to the P. unistrigatus species group, such as P. parvillus, P. luteolateralis, P. walkeri, among others. The new species of Pristimantis is a miniaturized new frog (females 17.1±1.1 mm; males 13.2±0.9 mm), characterized by the presence of “› ‹”-shaped scapular folds, with two subconical tubercles on the medial and posterior regions of folds; tympanic membrane and tympanic annulus present but not externally visible; a prominent rostral papilla present; upper eyelid with one elongated conical tubercle; a conical tubercle on heels; groin with orange or yellow spots. The new species of Pristimantis is distributed in a restricted area in the Cordillera del Condor, a highly-diverse mountain range threatened by multiple anthropogenic activities. We recommend assigning the new species to the Endangered IUCN threatened category because it is only known from three nearby localities within mining concessions.

Tillandsia oliveirae (Bromeliaceae): a new species from an inselberg in Bahia, Brazil

The authors describe, discuss, and illustrate Tillandsia oliveirae, a new species from the inselbergs of the Caatinga biome in the municipality of Itatim, Bahia, Brazil. The new species is similar to T. hofackeri, differing by morphological characters such as larger size of the plant, longer peduncle, more laxly arranged leaves, which are more numerous, and whitish petals. It is an endemic species with a restricted area of distribution, being considered critically endangered (CR) due to illegal extractivism, specifically for regional and international trade.

Performance Evaluation of MU-MIMO Transmissions with Joint Interference Constraint in HetNet

In this paper, we investigate the per-tier outage probability of multiuser multiple-input multiple-output (MU-MIMO) transmissions in heterogeneous networks (HetNets) with joint interference constraint. In the tier of cellular cell, user equipment (UE) is required to report measured channel information and the base station (BS) adopts ZF-based precoding MU-MIMO transmission to achieve multiuser diversity gain. With the constraint of cross-tier interference and unpredicted inter-beam interference, we derive the closed-form expression of outage probability of downlink MU-MIMO transmissions. Considering the capacity of nodes in the tier of ad hoc networks, a max-SINR scheduler and codebook-based MU-MIMO transmission are employed. The scheduler selects the best receiving nodes for each beam in predefined codebook according to measured signal to interference plus noise ratio (SINR), and the transmitting node performs data transmissions using orthogonal beams. In the presence of inter-node interference, inter-beam interference, and cross-tier interference, we obtain the closed-form expression of outage probability of MU-MIMO transmissions when downlink or uplink transmissions occur in cellular cell. Additionally, in case that the outage probability in ad hoc networks should satisfy quality of service (QoS) requirement, a restricted area in cellular cell in which the outage probability in ad hoc networks is not greater than a required threshold is explored. Numerical results show that the unpredictable inter-beam interference in cellular cell degrades the outage probability slightly. The restricted area increases with the outage probability threshold.

Macaronesia Acts as a Museum of Genetic Diversity of Relict Ferns: The Case of Diplazium caudatum (Athyriaceae)

Macaronesia has been considered a refuge region of the formerly widespread subtropical lauroid flora that lived in Southern Europe during the Tertiary. The study of relict angiosperms has shown that Macaronesian relict taxa preserve genetic variation and revealed general patterns of colonization and dispersal. However, information on the conservation of genetic diversity and range dynamics rapidly diminishes when referring to pteridophytes, despite their dominance of the herbaceous stratum in the European tropical palaeoflora. Here we aim to elucidate the pattern of genetic diversity and phylogeography of Diplazium caudatum, a hypothesized species of the Tertiary Palaeotropical flora and currently with its populations restricted across Macaronesia and disjunctly in the Sierras de Algeciras (Andalusia, southern Iberian Peninsula). We analysed 12 populations across the species range using eight microsatellite loci, sequences of a region of plastid DNA, and carry out species-distribution modelling analyses. Our dating results confirm the Tertiary origin of this species. The Macaronesian archipelagos served as a refuge during at least the Quaternary glacial cycles, where populations of D. caudatum preserved higher levels of genetic variation than mainland populations. Our data suggest the disappearance of the species in the continent and the subsequent recolonization from Macaronesia. The results of the AMOVA analysis and the indices of clonal diversity and linkage disequilibrium suggest that D. caudatum is a species in which inter-gametophytic outcrossing predominates, and that in the Andalusian populations there was a shift in mating system toward increased inbreeding and/or clonality. The model that best explains the genetic diversity distribution pattern observed in Macaronesia is, the initial and recurrent colonization between islands and archipelagos and the relatively recent diversification of restricted area lineages, probably due to the decrease of favorable habitats and competition with lineages previously established. This study extends to ferns the concept of Macaronesia archipelagos as refugia for genetic variation.

Earliest evidence of herd-living and age segregation amongst dinosaurs

Sauropodomorph dinosaurs dominated the herbivorous niches during the first 40 million years of dinosaur history (Late Triassic–Early Jurassic), yet palaeobiological factors that influenced their evolutionary success are not fully understood. For instance, knowledge on their behaviour is limited, although herding in sauropodomorphs has been well documented in derived sauropods from the Late Jurassic and Cretaceous. Here we report an exceptional fossil occurrence from Patagonia that includes over 100 eggs and skeletal specimens of 80 individuals of the early sauropodomorph Mussaurus patagonicus, ranging from embryos to fully-grown adults, with an Early Jurassic age as determined by high-precision U–Pb zircon geochronology. Most specimens were found in a restricted area and stratigraphic interval, with some articulated skeletons grouped in clusters of individuals of approximately the same age. Our new discoveries indicate the presence of social cohesion throughout life and age-segregation within a herd structure, in addition to colonial nesting behaviour. These findings provide the earliest evidence of complex social behaviour in Dinosauria, predating previous records by at least 40 My. The presence of sociality in different sauropodomorph lineages suggests a possible Triassic origin of this behaviour, which may have influenced their early success as large terrestrial herbivores.

DEVELOPMENT OF THE "SMART HOUSE" CONTROL SYSTEM

The proposed system allows you to control the parameters of the house using a remote control system. Changes in temperature and humidity in the house are monitored by telephone. The entire lighting system of the house is controlled. If a gas leak or fire occurs in the house, an alarm is triggered and a notification is sent to the phone. If there is unauthorized access to the house, this is detected by a motion sensor and a notification is sent to the phone. Changes in the apartment, which is "under the control" of the system, can be monitored and managed in the "Serial Monitor" section. Selected optical sensors are sensors that capture an optical image and work by analyzing the darkest and brightest parts of the image using algorithms. The level of security increases depending on the sensor's sensing element, so the higher the sensor's resolution, the better the image details. The ultrasonic signal is transmitted to the finger located on the scanner. Due to the presence of pores and other details that are characteristic of each fingerprint, part of this signal is absorbed, and part is returned to the sensor. As a result, the sensor can recognize fingerprints. Password authorization. A password based door lock system is an access control system that allows only authorized persons to enter a restricted area. When an authorized person enters the user ID and password from the keyboard, the door opens and after a few minutes the door closes again. If the code is entered incorrectly three times in a row, the code lock will go into blocking mode. Keywords: "smart house", control system, temperature sensor, motion sensor, telediagnostics, telecontrol.

Geochemical and Isotope Characterisation of Thermo-Mineral Springs of Corsica Island: From Geological Complexity to Groundwater Singularity

Understanding hydrogeological processes at the origin of thermal and mineral groundwater are necessary to ensure their sustainable management. However, many processes are involved in their genesis and often only one or two processes are investigated at the same time. Here, we propose to use an innovative combination of geochemical, isotopic (34S, 14C, 18O, 2H) and geothermometry tools to identify, for the first time in a multi-composite geological context, all processes at the origin of diversified thermo-mineral waters. 19 springs covering a wide range of temperature and chemical composition emerging on a restricted area of Corsica Island (France) were selected. Geochemical results highlight five geochemical provinces, suggesting a common origin for some of them. Geothermometry tools show the unexpected involvement of a common deep groundwater reservoir within this non-active zone. Water stable isotopes highlight a contrasted altitude in recharge areas supplying lowland springs. This suggests that different flow patterns have to be involved to explain the wide geochemical diversity observed and to allow the design of a very first conceptual groundwater-flow model. This paper demonstrates the efficiency of the combination of the selected tools as tracers of water–rock interaction, independently of flow depth, intrinsic water properties, geological conditions and interaction time disparities.