Symmetries and symmetry-breaking play significant roles in data security. While remote sensing images, being extremely sensitive geospatial data, require protection against tampering or destruction, as well as assurance of the reliability of the data source during application. In view of the increasing complexity of data security of remote sensing images, a single watermark algorithm is no longer adequate to meet the demand of sophisticated applications. Therefore, this study proposes a dual watermarking algorithm that considers both integrity authentication and copyright protection of remote sensing images. The algorithm utilizes Discrete Wavelet Transform (DWT) to decompose remote sensing images, then constructs integrity watermark information by applying Chebyshev mapping to the mean of horizontal and vertical components. This semi-fragile watermark information is embedded into the high-frequency region of DWT using Quantization Index Modulation (QIM). On the other hand, the robust watermarking uses entropy to determine the embedding position within the DWT domain. It combines the stability of Singular Value Decomposition (SVD) and embeds the watermark according to the relationship between the singular values of horizontal, vertical, and high-frequency components. The experiment showed that the proposed watermarking successfully maintains a high level of invisibility even if embedded with dual watermarks. The semi-fragile watermark can accurately identify tampered regions in remote sensing images under conventional image processing. Moreover, the robust watermark exhibits excellent resistance to various attacks such as noise, filtering, compression, panning, rotating, and scaling.
Objective The objective of this study was to identify the biological correlation between the tongue coating color and oral and gut micro-characteristics in metabolic-associated fatty liver disease (MAFLD) patients. Method The characteristics of the tongue coating were examined using an automatic tongue diagnosis system. Tongue coating and stool samples were collected from 38 MAFLD patients, and 16S rDNA full-length assembly sequencing technology (16S-FAST) was used for bioinformatic analysis. Results Twenty-two and 16 subjects were included in two distinct clusters according to the white/yellow color of the tongue coating, which was assessed by the L*a*b* values of the image. Upon analyzing the microorganisms in the tongue coating, 66 and 62 pathognomonic bacterial genera were found in the White and Yellow Coating Groups, respectively. The abundance of Stomatobaculumis positively correlated with the a* values of the tongue coating in the White Coating Group, while Fusobacterium , Leptotrichia , and Tannerella abundance was significantly correlated with the b* values in the Yellow Coating Group. Function prediction mainly showed the involvement of protein families related to BRITE hierarchies and metabolism. The MHR (MONO%/high-density lipoprotein cholesterol) of the Yellow Coating Group was higher than that of the White Coating Group. Conclusion In MAFLD patients, lower a* values and higher b* values are indicators of a yellow tongue coating. There were also significant differences in the flora of different tongue coatings, with corresponding changes in the intestinal flora, indicating a correlation between carbohydrate metabolism disorders and inflammation in the oral microbiome.
A mathematical model is built for the prediction of operation parameters for tritiated water transferred by air from nuclear reactors. Exhaust moist gas containing tritiated water vapor is emitted and diffused into the atmosphere. It should be ensuring that no condensate water formation during the mixture of exhaust moist gas and atmosphere to avoid local radiation. The occurrence of water condensation during the mixture of exhaust moist gas and atmospheric air is analyzed according to a fitting equation of saturated moist gas in a psychrometric chart. The mathematical model which predict operation temperature and RH of exhaust moist gas for certain atmospheric temperature and RH is built. The mathematical model is verified in CFD for five typical operating conditions. The effect of atmosphere temperature/RH on operation temperature and RH is analyzed. The operation strategy for tritiated water transferred by air under different atmospheric conditions is discussed and presented.
Digital watermarking is an effective method of vector map copyright protection. However, the topology and geometric features are potentially influenced by the disturbances of vertices caused by watermark embedding, thus reducing the availability of watermarked vector maps. In this research, we propose a post-correction method for two-dimensional vector map watermarking, by which the topology and geometric features of the input data can be preserved, while using only conventional watermarking techniques. In the proposed method, the Maximum Perturbation Regions (MPR) of vertices and direction angle constraints methods of adjacent lines are adopted to undergo multi-azimuth checks of watermarked vertices, which may cause changes of the geometric features and topology. After that, the coordinate adjustment method which is based on the homonymous vertices topology association and the MPR are combined for topology and geometric feature correction. For watermark embedding, two classic frequency domain watermarking techniques, Discrete Fourier Transformation (DFT) and Discrete Wavelet Transformation (DWT), phase based and low-frequency coefficient based respectively, are also adopted. The scheme was conducted on a building vector map and a road vector map. The experimental results show that the proposed method can ensure the topology consistency and geometric feature similarity of vector maps before and after embedding watermarks. Moreover, this method has little interference with the maps, which improves the usability of the watermarked vector map.
Performance of three kinds of bridge-type fault current limiters (BTFCLs) for enhancing low-voltage-ride-through (LVRT) capability of DFIG is evaluated in this paper. The common BTFCL can effectively enhance the LVRT capability of DFIG. However, the fault-current-limiting inductor (FCLI) is periodically inserted into the stator circuit under normal operation for compensating power losses of the FCLI. The periodically insertion of the FCLI induces stator voltage spikes, which causes significant stator flux and electromagnetic torque oscillations. One feasible way to solve this problem is to use an additional current-regulating circuit (CRC). However, the additional CRC increases hardware cost, reduces reliability of the whole system, and induces more power losses. To solve this problem, a BTFCL with bypass resistor (BTFCL-BR) is presented. The BR absorbs the majority of the current harmonics during normal operation and eliminates the stator voltage spikes. The flux and electromagnetic torque oscillations can thus be significantly reduced. The performance of three kinds of BTFCLs is evaluated by simulation and experimental studies on a typical 1.5 MW wind turbine driven DFIG system and a 2 kW DFIG prototype. By simulation and experimental evaluations, it seems that the BTFCL-BR approach is the most promising solutions among the three kinds of BTFCLs.
There is extensive evidence that rising atmospheric carbon dioxide concentration, [CO ] can stimulate rice yields. However, such increases are associated with a ubiquitous decline in nutrition, including protein, iron (Fe) and zinc (Zn). To determine the basis for these declines, we used gmo rice lines to test and compare the quantitative and qualitative metrics relative to their non-gmo counterparts at elevated [CO ] in situ . The gmo / non-gmo paired comparisons were associated with three phenological / metabolomic characteristics: (1) increased stomatal conductance, (2) an enlarged root system, and (3) enhanced nitrate absorption. All gmo lines showed a significantly higher percent stimulation of seed yield relative to their paired non-gmo cultivar at elevated [CO ]. Qualitatively, relative to non-gmos, leaf nitrogen and brown rice protein were not significantly reduced and for (1) and (2) the gmo lines showed no decline in Fe and Zn with elevated [CO ]. These findings do not, de facto , represent a gmo “solution” to [CO ] induced nutritional decay; however they provide the first evidence that gmo lines related to specific traits could be fundamental in selecting qualitative and quantitative responses of global rice to maintain yield and nutritional integrity in response to projected increases in atmospheric [CO ].
This paper studies such a problem that the faults recovery are independent and cannot be coordinated quickly in the transmission and distribution dispatching after the fault of the transmission network induces the outage of distribution network. Based on the power flow calculation and coordination information interaction of transmission and distribution, the transmission and coordination fault recovery strategy and the transmission and distribution coordinated power flow checking technology research are carried out. Through the integrated transmission and distribution model, the data of the real-time section of the transmission and distribution network is retrieved, and the coordinative fault recovery strategy is generated online, the coordination of the transmission and distribution network under the large-scale power outage failure are realized and the secondary fault caused by the coordination problem are avoided. The related demonstration application effectively improves the efficiency of the transmission and distribution network dispatchers in handling faults.
The new type of excavator based on multi degree-of-freedom controllable mechanism is a typical nonlinear multi-input-multi-output (MIMO) system, of which the closed chain constraints make it with strong coupling relationships. Consequently, the classic PID control method is not able to satisfy the control demands of the system. This paper introduces a fuzzy adaptive PID control method focusing on the improvement of the control accuracy of the excavator based on fuzzy logic inference according to the actual response of the control system, aiming at the automatically online adjusting of the PID parameters. A simulation study is also proposed. The correctness and validity of the project is verified by comparing the simulation results of the fuzzy adaptive PID controller with those of the classic PID controller. Results show that the former one designed for the new mechanical excavator has shorter settling time, and with less overshoot, than the latter one.
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