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The content of total nitrogen, phosphorus and potassium in the soil is an important basis for calculating the best fertilization amount and realizing the reasonable fertilization of the orange planting soil in time and accurately. In this research, hyper-spectral technology is applied to detect the three soil nutrient elements in the cultivated soil of citrus trees. Four spectral bands with central wavelengths of 660, 780, 870 and 970 nm and width of 20 nm are selected to measure the spectral reflectance of the potted kumquats canopy by hand-held spectrometer. At the same time, the content of total nitrogen, phosphorus and potassium in the cultivated soil of kumquat is determined using traditional methods. The correlation between the spectral information of kumquat canopy and the content of soil nutrient elements is analyzed by correlation coefficient method. The prediction model of soil nutrient element content based on the spectral information is established by multiple linear regression method. The results showed that the total potassium content of soil is significantly correlated with the spectral reflectance at 660 nm wave band and significantly correlated with the spectral indexes of R660/R780, R660/R870 and R660/R970. R2 of the prediction model of total potassium content established on the basis of spectral reflectance and ratio spectral index of the selected band is 0.756 and 0.857 respectively, which shows good prediction effect of the model. There is no significant correlation between the spectral reflectance and ratio spectral index of the selected band towards the total soil nitrogen and phosphorus content and it cannot be used for the rapid measurement of total nitrogen and phosphorus content. Further study is needed to select suitable spectral band and spectral index.

Additional file 3: Figure S3. Transect (path) and water source.

Additional file 1: Figure S1. Method of larvae collection and definition of piles of feces.

Additional file 2: Figure S2. Drinking path of equids.

Citrus segmentation is a key step of automatic citrus picking. While most current image segmentation approaches achieve good segmentation results by pixel-wise segmentation, these supervised learning-based methods require a large amount of annotated data, and do not consider the continuous temporal changes of citrus position in real-world applications. In this paper, we first train a simple CNN with a small number of labelled citrus images in a supervised manner, which can roughly predict the citrus location from each frame. Then, we extend a state-of-the-art unsupervised learning approach to pre-learn the citrus's potential movements between frames from unlabelled citrus's videos. To take advantages of both networks, we employ the multimodal transformer to combine supervised learned static information and unsupervised learned movement information. The experimental results show that combing both network allows the prediction accuracy reached at 88.3$\%$ IOU and 93.6$\%$ precision, outperforming the original supervised baseline 1.2$\%$ and 2.4$\%$. Compared with most of the existing citrus segmentation methods, our method uses a small amount of supervised data and a large number of unsupervised data, while learning the pixel level location information and the temporal information of citrus changes to enhance the segmentation effect., Comment: 7 pages,4 figures,Prepare for submission

Additional file 1: Figure S1. Area between two transects.

Over 20 billion Internet of Things devices are set to come online by 2020. Protecting such a large number of underpowered, UI-less, network-connected devices will require a new security paradigm. We argue that solutions dependent on vendor cooperation such as secure coding and platform changes are unlikely to provide adequate defenses for the majority of devices. Similarly, regulation approaches face a number implementation challenges which limit their effectiveness. As part of the new paradigm, we propose IDIoT, a network security policy enforcement framework for IoT devices. IDIoT prevents widespread network attacks by restricting IoT devices to only their necessary network behavior. IDIoT is simple and effective, building on decades of tried-and-true network security principles without requiring changes to the devices or cloud infrastructure.

In many regions both urban expansion and rural development take place simultaneously, and for the purpose of understanding the dynamic process of land use/cover change (LUCC) in such large areas, this study develops a multi—agent based land use model. Taking the Poyang Lake area of China as a typical case, this study applies the mechanism of diffusion—limited aggregation to simulate the behavior of urban agents, while rural land use is illustrated with a bottom—up based model consisting of agent and environment layers. In the agent layer, each household agent makes its own decisions on land use, and at each time interval a government agent takes control of land use by implementing policies. According to incomes and the rate of migrant workers, household agents are divided into six categories, among which different decision rules are followed. For complex LUCC in the Poyang Lake area of China from 1985 to 2005, the artificial society model developed in this study yields results highly consistent with observations. Importantly, it is shown that governmental policies can impose significant effects on the decisions of individual household agents on land use and the multi—agent—based land use model developed in this study provides a robust means for assessing the effectiveness of governmental policies.

This study provides an estimation of the eco-compensation requirements for forest ecosystem conservation in Hainan province of China using the ecological location quotient (ELQ). It determines that the ecosystem services provided by the forest ecosystem need to be classified into predominant, secondary and potential types. Consequently, the appropriate levels of payment are calculated using the ecological valuation coefficient (EVC) method. The mechanisms and standards of payment are then determined for the corresponding stages in the context of the eco-compensation concept. In this way, guidelines are provided for practising eco-compensation, not only in Hainan province but also in the other parts of China.

For indoor visible light communication (VLC) systems aim to achieve communication and illumination simultaneously, the channel capacity are significantly affected by illumination demands in actual scenarios. To enhance the system performance, the wavelength division multiplex (WDM) technique can be introduced. In this letter, we analyzed the demands of illuminance and chromaticity’s influence on indoor WDM visible light communication system based on color light emitting diodes (LED). The spectra distribution, crosstalk and noise of WDM VLC system were analyzed and the relative optimal total channel capacity was obtained by optimizing the number of sub-channels and their intensity at standard illumination scenario. It’s shown that by applying WDM technique, the total channel capacity of LED based VLC system can be about 4 times than the situation of single sub-channel, even with indoor illumination constraints. What’s more, the system performance can be improved by adjusting appropriate number of sub-channels and their intensity accordingly.

The shrinking and drying up of wetlands in arid and semiarid areas of China have been widely observed in the recent years, but there has been no consensus on whether the aggravation is caused by human activities or by global climate warming. For a better understanding of the cause, this study investigates the dynamic changes of Baiyangdian Lake wetland over the last 40 years. It is shown that since the 1980s, Baiyangdian Lake has suffered from an insufficient water input and shrunk considerably. By using SPSS11.0, this study undertakes a detailed analysis on the significance of the effects of the possible driving factors for the degradation. It is identified that the North China Plain has been warming up significantly in recent years, which causes a significant reduction in the precipitation and inflow to the lake. Although human disturbances such as the irrigation and storage of water in reservoirs do not play a decisive role, they accelerate the degradation and their effects should be minimized.

Cyber-physical systems integrate information and communication technology functions to the physical elements of a system for monitoring and controlling purposes. The conversion of traditional power grid into a smart grid, a fundamental example of a cyber-physical system, raises a number of issues that require novel methods and applications. In this context, an important issue is the verification of certain quantitative properties of the system. In this technical report, we consider a specific Chinese Smart Grid implementation and try to address the verification problem for certain quantitative properties including performance and battery consumption. We employ stochastic model checking approach and present our modelling and analysis study using PRISM model checker.