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With the continuous progress and development of robotics, mobile robots have been widely used in many different fields. In the power grid, mobile robots are used to inspect electrical equipment, which greatly reduce the investment of manpower and material resources. However, in many cases, mobile robots need to work in a constantly changing and complex environment. Because they cannot obtain environmental information in time, it is often difficult to make path planning. In response to this problem, this paper proposes a path planning method for mobile robots based on improved reinforcement learning. This method establishes a grid environment model, defines the return value through the number of steps of the robot, and then proposes a changing action selection strategy for the balance between the robot’s exploration and utilization of the environment in reinforcement learning, so that the exploration factor dynamically change with the increase of the robot’s exploration degree of the environment, thus speeding up the convergence speed of the learning algorithm. Simulation results show that this method can realize autonomous navigation and path planning of mobile robots in complex environments. Compared with traditional algorithms, it greatly reduces the number of iterations.

BACKGROUND It is important to understand whether older people are admitted into residential care with existing dental diseases or their oral health deteriorates while residing in residential care. There is, however, little research available exploring the oral health status of people newly admitted into residential care. Understanding this disease trend would lead to effective prevention and treatment strategies to be trialled and implemented prior to admission. In this cross-sectional study, we hypothesize that older people with one or more natural teeth might have poor oral health prior to admission to residential care. METHOD The study was carried out using the de-identified oral health assessment database of an established domiciliary oral health care program in metropolitan New South Wales, Australia. Four hundred and nine participants with mean participant age of 85.56 years from 13 facilities from 2015 to 2018 fulfilled the inclusion criteria for this study. CONCLUSION This study confirmed that dentate, newly admitted residents to residential care had pre-existing dental problems and oral health concerns. Almost half of the newly admitted residents had an unsatisfactory oral cleanliness score when examined in their residential care setting.

Intelligent cartoon image generation is to generate an image corresponding to a given text through a certain pattern. However, the absent of proportion and position information of each objects directly affects the quality of output image. This paper focuses on the optimization of the layout based on MCMC method and Metropolis-Hastings Algorithm. The proportion and position of each cartoon characters compose into a state and optimized with Metropolis-Hasting method iteratively. Poisson image fusion method is used to make the images fusion area transition smooth to reduce synthetic trace. Experimental results show that the algorithm in this paper can generate cartoons images intelligently.

Knowledge of the fracture hydraulic aperture and its relation to the mechanical aperture and normal stress is urgently needed in engineering construction and analytical research at the engineering field scale. A new method based on the in situ borehole camera measurement and borehole water-pressure test is proposed for the calculation of the fracture hydraulic aperture. This method comprises six steps. The first step is to obtain the equivalent hydraulic conductivity of the test section from borehole water-pressure tests. The second step is a tentative calculation to obtain the qualitative relation between the reduction coefficient and the mechanical aperture obtained from borehole camera measurements. The third step is to choose the preliminary reduction coefficient for obtaining the initial hydraulic aperture. The remaining three steps are to optimize, using the genetic algorithm, the hydraulic apertures of fractures with high uncertainty. The method is then applied to a fractured granite engineering area whose purpose is the construction of an underground water-sealed storage cavern for liquefied petroleum gas. The probability distribution characteristics of the hydraulic aperture, the relationship between the hydraulic aperture and the mechanical aperture, the hydraulic aperture and the normal stress, and the differences between altered fractures and fresh fractures are all analyzed. Based on the effects of the engineering applications, the method is proved to be feasible and reliable. More importantly, the results of the hydraulic aperture obtained in this paper are different from those results elicited from laboratory tests, and the reasons are discussed in the paper.

The Duobaoshan mineralization area is located in the northeast part of the Xing'an–Mongolia orogenic belt which belongs to the eastern part of the Central Asian Orogenic Belt (CAOB). This region has experienced multiple tectonic–magmatic–metallogenic events that resulted in a number of large–superlarge mineral deposits, e.g. the early Palaeozoic Duobaoshan and Tongshan porphyry Cu–Mo deposits, the early Mesozoic Sankuanggou skarn Fe–Cu deposit and Xiaoduobaoshan skarn Cu deposit and the late Mesozoic Zhengguang epithermal Au deposit. By detailed field survey, we have examined the weak alteration and mineralization in the tonalite veins intruding early Palaeozoic ore-bearing granodiorite in the Duobaoshan deposit and the veinlet-disseminated Cu–Mo mineralization in the porphyritic granite veins intruding in the ore-hosting Ordovician strata of the Duobaoshan Formation in the Tongshan deposit. Zircon grains from the Duobaoshan tonalite, the Tongshan porphyritic granite, and the metallogenic granite porphyry and the granodiorite in the Xiaoduobaoshan deposit yield LA–ICP–MS U–Pb weighted mean ages of 230.9 ± 2.3 Ma, 235.4 ± 2.7 Ma, 226.6 ± 1.7 Ma and 232.8 ± 1.7 Ma, respectively. In addition, the Re–Os model age of molybdenites from the Tongshan porphyritic granite is 229.4 ± 3.5 Ma. Those isotope dating results indicate that the Duobaoshan mineralization area experienced the Triassic magmatic–mineralization event. Considering the regional tectonic history of the area and the fact that the major and trace element characteristics of the Triassic tonalite in the Duobaoshan deposit are similar to those of island–arc type igneous rocks, it is presented that the Triassic magmatic–metallogenic event might be closely related to the subduction of the Mongolia–Okhotsk plate, and that the metallogenic elements originated from the mantle wedge metasomatized by liquid of subduction oceanic slab. Previous research and new geochemical analyses presented in this study indicate that the Duobaoshan mineralization area experienced at least four epochs of magmatic–metallogenic events including the Ordovician, the Triassic, the Early Jurassic and the Late Jurassic to Early Cretaceous. Copyright © 2015 John Wiley & Sons, Ltd.

The Duobaoshan ore field, a major center of metal production in Northeast China, is located in the northeast of the Xing’an–Mongolia Orogenic Belt (the eastern part of the Central Asian Orogenic Belt) and within the northern Greater Xing’an Mountains. Several types of ore deposits are mined in the Duobaoshan region, including the Duobaoshan and Tongshan porphyry copper–molybdenum deposits, the Sankuanggou skarn iron–copper deposit, and the Zhengguang epithermal gold deposit. Zircon grains from the Tongshan granodiorite and porphyritic granite yield laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) U–Pb weighted mean ages of 475.9 ± 0.8 Ma and 230.9 ± 0.9 Ma to 240.7 ± 0.8 Ma, respectively. The Re–Os isochron age of molybdenites from the Tongshan deposit is 473 ± 4 Ma. Because both field observations and petrographic analysis identified disseminated chalcopyrite, pyrite, and malachite in the porphyritic granite, the isotope dating indicates that the Tongshan deposit underwent at least two magmatic–mineralization events, during the Ordovician and the Triassic. Zircon grains from the metallogenic granodiorite of the Sankuanggou skarn deposit yield an age of 176.1 ± 0.3 Ma, and Re–Os dating of molybdenite gives an age of 173 ± 6 Ma, indicating a Jurassic event. Based on previous research and the new geochemical analysis presented in this study, it is inferred that the magmatism and mineralization of the Sankuanggou deposit were associated with the subduction of the Paleo-Pacific Plate. The Duobaoshan region has therefore experienced at least three major magmatic and mineralization events, during the Ordovician (470–480 Ma), the Triassic (230–240 Ma), and the Early Jurassic (170–180 Ma).

The Zhengguang deposit, a representative large gold deposit in the Duobaoshan ore field in NE China, is located in the northeast of the Central Asian Orogenic Belt (CAOB). Ore body emplacement was structurally controlled and occurs mainly at the contact zone between the strata of Duobaoshan Formation and an Ordovician diorite stock. The diorite rocks have a close genetic relationship with Au mineralization. Re–Os isotope dating of Au-bearing pyrite yields an isochron age of 506 ± 44 Ma (MSWD = 15). Based on present and previous dating results, it can be concluded that the Zhengguang deposit formed at ~480 Ma. The mineralization time of the Zhengguang deposit is nearly identical to those of the Duobaoshan and Tongshan deposits, indicating they are all derived from the same metallogenic system. The Duobaoshan-style porphyry Cu–Mo mineralization may exist at deeper levels at Zhengguang. The geochemical characteristics of the Zhengguang dioritic rocks presented in this paper are similar to those of bajaitic high-Mg andesite, and the magmas originated from a mantle wedge metasomatized by melts from a subducting oceanic slab at an active continental margin setting. The Ordovician magmatic–metallogenic events in the Duobaoshan ore field were caused by the westward subduction of an oceanic slab located between the Xing’an and Songliao blocks. It is worth pointing out that the Zhengguang deposit is the oldest known Phanerozoic Au deposit in NE China. Further studies of this deposit will improve understanding of the regularity of ore formation and aid mineralization forecast across the Duobaoshan region.

Doppler asymmetric spatial heterodyne spectroscopy (DASH) technique with the advantages of high spectral resolution and high phase sensitivity can be considered as a combination of the spatial heterodyne spectroscopy (SHS) technique and the Michelson interferometer technique, which is very suitable for high-precision passive measurement of Doppler velocity. Since a larger optical path difference offset in one of the spectrometer arms corresponds to a higher phase shift sensitivity while suffering a lower contrast of the interferogram, there is an optimum path difference offset for measuring the phase shift and thus the Doppler shift is most sensitive. By comprehensively considering the trade-off between the contrast and the phase shift sensitivity of the interferogram, in this paper we carry out theoretical analysis on the optimum path difference offset. Based on the efficiency function which is defined as the product of the optical path difference and the contrast of the interferogram, the mathematical expressions of the optimum path difference offset for the Gaussian and Lorentz type emission spectral lines are theoretically deduced, respectively. In order to verify these two mathematical expressions, a simulation analysis about the phase shifts of the interference fringes for a single Gaussian type emission spectral line is carried out. The simulation result is consistent with the theoretical value calculated by the deduced mathematical expression. In addition, concerning the complexity of the traditional data processing method for resolving the Doppler velocities of multiple spectral lines, a simplified data processing method based on partial interference fringes is proposed. In general, a single spectral line should be distinguished and isolated from multiple spectral lines in the traditional data processing method. If the distribution of the spectral lines in the passband is too dense, a DASH spectrometer with high enough spectral resolution will be needed. The proposed processing method, retrieving the Doppler velocity from multiple spectral lines without isolating a single line in frequency domain, can not only effectively reduce the calculation of data processing, but also lower the requirement for the spectral resolution of the DASH spectrometer. Combining it with the adaptive frequency-tracing algorithm, the simulation calculations of the Doppler velocity measurement process of the single and multiple spectral lines are conducted. The results show that without taking the noise into account, the maximum resolving errors derived from the proposed data processing method for single and multiple spectral lines are similar, both within 0.005 m/s. It indicates that the proposed data processing method can fully meet the accuracy requirement of practical application and shows the prospect of wide applications in the field of passive Doppler velocity measurement.

In order to raise the adapbility of SVM classification to the specific dataset, a composite kernel is proposed and introduced into SVM, and the parameters are optimized according to “Fisher Discriminant” and “Kernel Alignment”, to maximize the class separability in the empirical feature space and, make composite kernel to be more relevant for the dataset and adapt itself by adjusting its composed coefficient parameters, thus allowing more flexibility in the kernel choice. The performance of support vector machines based composite kernel (CK-SVM) is extensively evaluated on five UCI standard datasets, at the same time, we compare CK-SVM with other existing method and get convincing results, which reveal that the proposed method is a robust and promising classifier.